WeBWorK demonstration assignment - Math...70After ﬁrst logging into WeBWorK change your password....

WeBWorK demonstration assignment

The main purpose of this WeBWorK set is to fa-miliarize yourself with WeBWorK.

Here are some hints on how to use WeBWorK ef-fectively:

� After first logging into WeBWorK changeyour password.� Find out how to print a hard copy on the com-puter system that you are going to use. Printa hard copy of this assignment.� Get to work on this set right away and answerthese questions well before the deadline. Notonly will this give you the chance to figureout what’s wrong if an answer is not accepted,you also will avoid the likely rush and con-gestion prior to the deadline.� The primary purpose of the WeBWorK as-signments in this class is to give you the op-portunity to learn by having instant feedbackon your active solution of relevant problems.Make the best of it!

1.(1 pt) Determine whether the following examplesof data are quantitative or qualitative. Write ”QUAN-TITATIVE” for quantitative and ”CATEGORICAL”for categorical. (without quotations)

(a) The marital status of your coworkers.answer:

(b) The occupation of your neighbors.answer:

(c) Your college GPA.answer:

(d) The amount of bacteria on a piece of moldybread.answer:

2.(1 pt)

Grade on Statistics Exam FrequencyBelow 50 450 � 59 960 � 69 1470 � 79 1680 � 89 17

90 � 100 6

Given the frequency table above, construct the fol-lowing:

(a) The relative frequency table that correspondswith the above table.

Grade on Statistics Exam Relative FrequencyBelow 5050 � 5960 � 6970 � 7980 � 89

90 � 100

(b) The cumulative frequency table that corre-sponds with the above table.

Grade on Statistics Exam Cumulative FrequencyBelow 5050 � 5960 � 6970 � 7980 � 89

90 � 100

3.(1 pt)Each year ”Fortune” magazine lists the top 500 com-panies in the United States, ranked according to theirtotal annual sales in dollars. Choose from the list be-low other variables that could reasonably be used tomeasure the ”size” of a company.

� A. Price-to-earnings ratio� B. Total value of stock� C. Advertising-to-sales ratio� D. Total assets� E. The per-unit cost of production� F. Number of employees

4.(1 pt) For each of the given the data sets below,calculate the mean, variance, and standard deviation.

(a) 78 � 8 � 77 � 92 � 26 � 73 � 23 � 73 � 65mean � variance � standard deviation �

(b) 50 � 45 � 44 � 41 � 48 � 44mean � variance � standard deviation �

(c) 3 � 5 � 3 � 5 � 2 � 8 � 3 � 3 � 4mean � variance � standard deviation �

5.(1 pt) Calculate the mean and median of the fol-lowing grades on a math test:

86 � 81 � 76 � 74 � 72 � 71 � 71 � 66 � 61 � 47 � 211

Mean =Median =Is this data set skewed to the right, symmetric, or

skewed to the left?(Enter SR, SYM, or SL);

6.(1 pt) These are the grades on a math test:

89 � 90 � 87 � 95 � 86 � 81 � 102 � 105 � 83 � 88 � 91 � 79

a) Calculate the following (enter answer with twodecimals):

Mean =Median =Variance =Standard deviation =b) Compute the quartiles and the IQR (enter an-

swer with one decimal):Q1 =Q3 =IQR =c) Is this data set skewed to the right, symmetric,

or skewed to the left? (Enter SR, SYM, or SL);

d) Based on the shape of the distribution, wouldyou report the standard deviation or the quartiles as ameasure of spread? (Enter YES or NO)

7.(1 pt) The Environmental Protection Agency re-quires that the exhaust of each model of motor vehi-cle be tested for the level of several pollutants. Thelevel of oxides of nitrogen (NOX) in the exhaust ofone light truck model was found to vary among indi-vidual trucks according to a normal distribution withmean 1.45 grams per mile driven and standard devia-tion of 0.40 grams per mile.

(a) Give an interval that contains the middle 95%of NOX levels in the exhaust of trucks

to

8.(1 pt) A study of elite distance runners found amean weight of 63.1 kilograms (kg), with a standarddeviation of 4.8 kg. Use the 68-95-99.7 rule to an-swer the following questions:

(a) Find the interval centered at the mean that willinclude 99 � 7% of the weights of the elite runners�

µ�

(b) Find the interval centered at the mean that willinclude 95% of the weights of the elite runners�

µ�

(c) Find the interval centered at the mean that willinclude 68% of the weights of the elite runners�

µ�

9.(1 pt) Suppose the random variable x is best de-scribed by a normal distribution with µ � 28 andσ � 3 � 5. Find the z-score that corresponds to eachof the following x values.

(a) x � 20z �

(b) x � 18z �

(c) x � 29z �

(d) x � 35z �

(e) x � 16z �

(f) x � 11z �

10.(1 pt) Suppose x is a normally distributed ran-dom variable with µ � 10 � 4 and σ � 1 � 7. Find eachof the following probabilities:

(a) P � 8 � 4 � x�

14 � 2 ��(b) P � 5 � 4 � x

�13 � 1 ��

(c) P � 11 � 5 � x�

16 � 4 ��(d) P � x 10 ��(e) P � x � 13 � 1 ��11.(1 pt) The physical fitness of an athlete is often

measured by how much oxygen the athlete takes in(which is recorded in milliliters per kilogram, ml/kg).The mean maximum oxygen uptake for elite athleteshas been found to be 70 with a standard deviation of6 � 6. Assume that the distribution is approximatelynormal.

(a) What is the probability that an elite athlete hasa maximum oxygen uptake of at least 50 ml/kg?

answer:(b) What is the probability that an elite athlete has

a maximum oxygen uptake of 70 ml/kg or lower?answer:(c) Consider someone with a maximum oxygen

uptake of 29 ml/kg. Is it likely that this person is anelite athlete? Write ”YES” or ”NO.”

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answer:12.(1 pt) Find the value z of a standard normal

variable Z that satisfies each of the following con-ditions. (If you use Table A, report the valueof z thatcomes closest to satisfying the condition.) Enter an-swer with two decimals.

(a) The point z with 25 percent of the observationsfalling below it.

answer:(b) The point z with 40 percent of the observations

falling above it.answer:

Prepared by the WeBWorK group, Dept. of Mathematics, University of Rochester, c�

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1.(1 pt) Water flowing across farmland washesaway soil. Researchers released water across a testbed at different flow rates and measured the amountof soil washed away. The following table gives theflow (in litters per second) and the weight (in kilo-grams) of eroded soil.

Flowrate 0 � 31 0 � 85 1 � 26 2 � 47 3 � 75Erodedsoil 0 � 82 1 � 95 2 � 18 3 � 01 6 � 07

Based on the data in the table, answer the follow-ing questions (without using quotations).

(a) Plot the data. Which is the explanatory variable(enter flow rate or eroded soil)?answer:

(b) Would you describe the overall patern by astraight line or by a curve (answer straight line orcurve)?answer:

(c) Is the association positive or negative? (answerpositive or negative)answer:

2.(1 pt) Here are data on a group of people whocontracted botulism, a form of food poisoning thatcan be fatal. The variables recorded are the person’sage in years, the incubation period (the time in hoursbetween eating the infected food and the first signs ofillness), and whether the person survived (S) or died(D).

Person 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18Age 29 39 44 37 42 17 38 43 51 30 32 59 33 31 32 32 36 50

Incubation 13 46 43 34 20 20 18 72 19 36 48 44 21 32 86 48 28 16Outcome D S S D D S D S D D D S D D S D S D

(a) Make a scaterplot of incubation period againstage, using different symbols for people who survivedand those who died. Is there an overall relationshipbetween age and incubation period? Answer YES orNO.

answer:(b) Is there a relationship between either age

or incubation period and whether the victim sur-vived? Answer INCUBATION/SURVIVAL orAGE/SURVIVAL.answer:

(c) Is there any unusual observation that may re-quire individual investigation? Answer OBSERVA-TION X, where X represents a number from 1 to 18.

answer:3.(1 pt) Here are the golf scores of 11 members of

a women’s golf team in two rounds of college tourna-ment play:

Player 1 2 3 4 5 6 7 8 9 10 11Round1 89 90 87 95 86 81 105 83 88 91 79Round2 94 85 89 89 81 76 89 87 91 88 80

Based on the data in the table, answer the follow-ing questions (give answer with three decimals).

(a) Find the correlation between the Round 1 andRound 2 scores.answer:

(b) Remove Player 7’s score and find the correla-tion for the remaining 10 players.answer:

4.(1 pt) Fred keeps his savings in his mattress. Hebegins with 500 dollars from his mother and adds 100dollars each year. His total savings y after x years are

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given by the equation y = 500 +100x. Draw a graphof this equation (on paper only). Answer the follow-ing questions:

(a) After 20 years, how much will Fred have in hismattress?answer: dollars

(b) If Fred adds 200 dollars instead of 100 dollarseach year to his initial 500, what is the equation thatdescribes his savings after x years?answer: y = + x

5.(1 pt) Manatees are large, gentle sea creaturesthat live along the Florida coast. Many manateesare killed or injured by powerboats. The table belowgives data on powerboat registrations (in thousands)and the number of manatees killed by boats in Floridain the years 1977 to 1990.

Year 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990Boats � thousands � 447 460 481 498 513 512 526 559 585 614 645 675 711 719Manateeskilled 13 21 24 16 24 20 15 34 33 33 39 43 50 47

Based on the data in the table, answer the follow-ing questions:

(a) Plot the data and describe the form and direc-tion of the relationship. Your answer should be ofthe form: FORM/DIRECTION (for form, choose be-tween linear or curve, for direction choose betweenpositive or negative).answer:

(b) Find the correlation. Enter answer with 4 deci-mals.answer:

(c) What fraction of the variation in manatee deathscan be explained by the number of boats registered?Enter answer with one decimal.answer: percent

(d) Does it appear that the number of manateeskilled can be predicted accurately from powerboatregistrations? Answer YES or NO.answer:

(e) Find the least-squares regression line. In thefirst box enter the value for a, and in the second boxenter the value for b.(enter answer with three deci-mals)answer: y = + x

(f) Predict the number of manatees that will bekilled by boats in a year when 716,000 powerboatsare registered. (Hint: Predict the number of mana-tees in thousands (see the table), that is, report theresult in the form X thousands(without writing theword ’thousands’).answer: thousands

(g) Suppose that in some far future year 2 millionpowerboats are registered in Florida. Use the regres-sion line to predict manatees killed.answer: manatees

(h) Is the prediction in point (g) reliable? AnswerYES or NO.answer:

6.(1 pt) A business school conducted a survey ofcompanies in its state. They mailed a questionare to200 small companies, 200 medium-sized comapnies ,and 200 large companies. The rate of nonresponse isimportant in deciding how reliable survey results are.Here are the data on response to this survey:

Response No response TotalSmall 125 75 200

Medium 81 119 200Large 40 160 200

Based on the table above, answer the followingquestions (give answer with one decimal):

(a) What describes the overall percent of nonre-sponse?

answer: percent did not respond.(b) Describe how nonresponse is related to the size

of the business. (Use percents to make your state-ments precise.)

answer: percent of small businesses did notrespond

answer: percent of medium-sized businessesdid not respond

answer: percent of large businesses did notrespond

(c) Using the total number of responses as a base,compute the percent of responses that come fromeach of small, medium, and large businesses (enteranswer with one decimal, without rounding up).

Small: percentMedium: percentLarge: percent

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1.(1 pt) Determine whether the following descrip-tions correspond to an observational study or anexperiment. Write ”EXPERIMENT” for experi-ment and ”OBSERVATION” for observational study.(without quotations)

(a) A new antibiotic is tested in effectiveness byrecording how the drug works on patients that alreadytake the drug.answer:

(b) The effectiveness of lecture teaching is testedwith a sample of students who has completed numer-ous lecture style courses.answer:

(c) A new study examines how efficiently althletesburn calories by limiting their diets.answer:

2.(1 pt) An educator wants to compare the effec-tiveness of computer software that teaches readingwith that of a standard reading curriculum (TEACH-ING METHOD). She tests the reading ability of eachstudent in a class of fourth graders, then divides theminto two groups. One group uses the computer reg-ularly, while the other studies a standard curriculum.

At the end of the year, she retests all the students andcompares the increase in reading ability in the twogroups (READING ABILITY).

(a) What is the explanatory variable? (Choosebetween TEACHING METHOD and READINGABILITY).Explanatory variable:

(b) What is the response variable? (Choosebetween TEACHING METHOD and READINGABILITY).Response variable:

(c) Is this an experiment or an observational study?(Write OBSERVATION OR EXPERIMENT)answer:

3.(1 pt)The National Halothan Study was a major investi-gation of the safety of anesthetics used in surgery.Records of over 850,000 operations performed in 34major hospitals showed the following death rates forfour common anesthetics:

Anesthetic A B C DDeath Rate 1 � 7% 1 � 7% 3 � 4% 1 � 9%

There is a clear association between the anestheticused and the death rate of patients. Anesthetic Cappears dangerous. When the study looked at othervariables that are confounded with the choice of theanesthetic that a doctor makes, it found that Anes-thetic C was not causing extra deaths. Suggest othervariables that are mixed up with what anesthetic a pa-tient received. Mark all the variables that you con-sider suitable.

� A. sex of the patient� B. type of surgery performed� C. age of the patient� D. condition of the patient� E. income of patient� F. choice of hospital where operation is per-formed� G. state of residence of patient

4.(1 pt) A carload of ball bearings has a mean di-ameter of 2.503 centimeters (cm). This is within thespecifications for acceptance of the lot by the pur-chaser. The inspector happens to inspect 100 bear-ings from the lot with a mean diameter of 2.515 cm.

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This is outside the specified limits, so the lot is mis-takenly rejected.

(a) State whether each of the two numbers belowis a parameter or a statistic. Enter PARAMETER orSTATISTIC.2.503 is a:

2.515 is a:5.(1 pt) A researcher investigating the effects of a

toxic compound in food conducts a randomized com-parative experiment with young male white rats. A

control group is fed a normal diet, while the exper-imental group is fed a diet with 2500 parts per mil-lion of the toxic material. After 8 weeks, the meanweight gain is 335 grams for the control group and289 grams for the experimental group.

(a) State whether each of the two numbers belowis a parameter or a statistic. Enter PARAMETER orSTATISTIC.335 is a:

289 is a:


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1.(1 pt)Hold a penny upright on its edge under your fore-finger on a hard surface, then snap it with your otherforefinger so that it spins for some time before falling.Based on 50 spins, what is the probability of heads?Choose one:

� A. Long trials of this experiment often ap-proach 50 % heads� B. Long trials of this experiment often ap-proach 60 % heads� C. Long trials of this experiment often ap-proach 40 % heads

2.(1 pt) When we toss a penny, experience showsthat the probability (long-term proportion) of a headis close to 1/2. Suppose now that we toss the pennyrepeatedly until we get a head. What is the proba-bility that the first head comes up in an odd numberof tosses (1,3,5, and so on)? To find out, repeat thisexperiment 50 times, and keep a record of the num-ber of tosses needed to get a head on each of your 50trials. Write your answers as a fraction (for example,a/b).

(a) From your experiment, estimate the probabil-ity of a head on the first toss. What value should weexpect this probability to have?answer:

(b) Use your results to estimate the probability thatthe first head appears on an odd-numbered toss.answer:

3.(1 pt) If you draw an MM candy at random froma bag of candies, the candy you draw will have oneof six colors. The probability of drawing each colordepends on the proportion of each color among allcandies made.

a) The table below gives the probability of eachcolor for a randomly chosen plain MM:

Color Brown Red Yellow Green Orange BlueProbability 0 � 3 0 � 2 0 � 2 0 � 1 0 � 1 ?

What must be the probability of drawing a bluecandy?

answer:b) The probabilities for peanut MM’s are a bit dif-

ferent. Here they are:

Color Brown Red Yellow Green Orange BlueProbability 0 � 2 0 � 1 0 � 2 0 � 1 0 � 1 ?

What is the probability that a peanut MM chosen atrandom is blue?

answer:c) What is the probability that a plain MM is any

of red, yellow, or orange?answer:d)What is the probability that a peanut MM has one

of these colors (red, yellow, or orange) ?answer:4.(1 pt) A sociologist studying social mobility in

Denmark finds that the probability that the son of alower class father remains in the lower class is 0.46.

(a) What is the probability that the son moves toone of the higher classes?answer:

5.(1 pt) Government data assign a single cause foreach death that occurs in the United States. The datashow that the probability is 0.45 that a randomly cho-sen death was due to cardiovascular (mainly heart)disease, and 0.22 that it was due to cancer.

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(a) What is the probability that a death was due ei-ther to cardiovascular disease or to cancer?answer:

(b) What is the probability that the death was dueto some other cause?answer:

6.(1 pt) A sample space contains 7 sample pointsand events A and B as seen in the Venn diagram.

Let P � 1 �� P � 2 �� P � 3 �� P � 7 �� 0 � 05P � 4 �� P � 5 �� 0 � 1and P � 6 �� 0 � 6.

Use the Venn diagram and the probabilities of thesample points to find:

(a) P � A ��(b) P � B ��(c) P � Ac B ��(d) P � Ac ��7.(1 pt) An automobile manufacturer buys com-

puter chips from a supplier. The supplier sends ashipment containing 5% defective chips. Each chipchosen from this shipment has probability 0.05 of be-ing defective, and each automobile uses 12 chips se-lected independently.

(a) What is the probability that all 12 chips in a carwill work properly? Enter answer with 4 digits afterthe decimal point, without rounding up.answer:

8.(1 pt)Can you conclude that because (0.27)(0.16) = 0.043,about 4 percent of the labor force are college-educated laborers or operators?

� A. No. It is unlikely that these events are in-dependent. In particular, it is reasonable toexpect that college graduates are less likelyto be laborers or operators.� B. Yes, since these events are most of the timeindependent.

9.(1 pt) The gene for albinism in humans is reces-sive. That is, carriers of this gene have probability1/2 of passing it to a child, and the child is albinoonly if both parents pass the albinism gene. Parentspass their genes independently of each other. Answerthe following questions entering the results as a ratio.

(a) If both parents carry the albinism gene, what isthe probability that their first child is albino?answer:

(b) If they have two children (who inherit indepen-dently of each other), what is the probability that bothare albino?answer:

(c) If they have two children (who inherit indepen-dently of each other), what is the probability that nei-ther is albino?answer:

10.(1 pt) The ”random walk” theory of securityprices holds that price movements in disjoint timeperiods are independent of each other. Suppose thatwe record only whether the price is up or down eachyear, and that the probability that our portfolio rises inprice in any one year is 0.65. (This probability is ap-proximately correct for a portfolio containing equaldollar amounts of all common stocks listed on theNew York Stock Exchange). Answer the followingquestions:

(a) What is the probability that our portfolio goesup for three consecutive years? Enter answer withfour digits after the decimal point.answer:

(b) If you know that the portfolio has risen in price2 years in a row, what probability do you assign tothe event that it will go down next year? Enter an-swer with 2 digits after the decimal point.answer:

(c) What is the probability that the portfolio’s valuemoves in the same direction in both of the next 2years? Enter answer with 3 digits after the decimalpoint.

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answer:11.(1 pt) A study of education followed a large

group of fifth-grade children to see how many yearsof school they eventually completed. Let X be thehighest year of school that a randomly chosen fifthgrader completes. (Students who go on to college areincluded in the outcome X = 12). The study foundthis probability distribution:

Years 4 5 6 7 8 9 10 11 12Probability 0 � 010 0 � 007 0 � 007 0 � 013 0 � 032 0 � 068 0 � 070 0 � 041 0 � 752

(a) What percent of fifth graders eventually fin-ished twelfth grade? (Enter the answer with one digitafter the decimal point)answer:

(b) Find P � X 6 � (the event includes the value 6).Enter answer with 3 digits after the decimal point.answer:

(c) Find P � X � 6 � . Enter answer with 3 digits afterthe decimal point.answer:

(d) Find the probability of the event ¡the studentcompleted at least one year of high school¿. (enterthe answer with three digits after the decimal point)answer:

12.(1 pt) Let the random variable X be a randomnumber with the uniform density curve between 0 and1. Find the following probabilities:

(a) P � X �0 � 49 � (enter answer with 2 digits after

the decimal point)answer:

(b) P � X 0 � 27 � (enter answer with 2 digits afterthe decimal point)answer:

(c) P � 0 � 27 � X � 1 � 27 � (enter answer with 2 digitsafter the decimal point)answer:

(d) P � 0 � 1 � X�

0 � 2or0 � 8 � X�

0 � 9 � (enter answerwith 1 digit after the decimal point)

answer: (e) The probability thatX is not in the interval 0.3 to 0.8. (enter answer with1 digit after the decimal point)

answer: (f) P � X � 0 � 5 �answer:13.(1 pt) An opinion poll asks an SRS of 1500

adults, ”Do you happen to jog?”. Suppose that the

population porportion who jog (a parameter) is p =0.15. To estimate p, we use the proportion p* inthe sample who answer ”Yes”. The statistic p* is arandom variable that is approximately normally dis-tributed with mean equal to 0.15 and standard devi-ation 0.0092. Find the following probabilities (enteranswer with four digits after the decimal point):

(a) P � p �� 0 � 16 �answer:

(b) P � 0 � 14�

p � � 0 � 16 �answer:

Hint: Round up the z-scores to two digits after thedecimal point.

14.(1 pt) The distribution of grades in a largecourse is as follows (A=4, B=3 and so on):

Grade 0 1 2 3 4Probability 0 � 10 0 � 15 0 � 30 0 � 30 0 � 15

(a) Find the mean of the distribution of grades inthis course. Enter answer with 2 digits after the deci-mal point.answer:

15.(1 pt) In a process for manufacturing glassware,glass stems are sealed by heating them in a flame.The temperature of the flame varies a bit. Here is thedistribution of the temperature X measured in degreesCelsius:

Temperature 540 545 550 555 560Probability 0 � 1 0 � 25 0 � 3 0 � 25 0 � 1

(a) Find the mean temperature of X.answer: degrees Celsius(b) Find the standard deviation of X (give answerwith three digits after the decimal point).answer: degrees Celsius(c) The target temperature is 550 celsius degrees.What is the mean of the number of degrees off tar-get X - 550?answer: degrees Celsius(d) What is the standard deviation of the number ofdegrees off target X - 550? (give answer with threedigits after the decimal point)answer: degrees Celsius

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(e) A manager asks for results in degrees Fahrenheit.The conversion of X into degrees Fahrenheit is givenby Y = (9/5)X + 32. What is the mean of Y?answer: degrees Fahrenheit(f) What is the standard deviation of Y?(give answerwith two digits after the decimal point)answer: degrees Fahrenheit

16.(1 pt) In an experiment on the behavior ofyoung children, each subject is placed in an area withfive toys. The response of interest is the number oftoys that the child plays with. Past experiments withmany subjects have shown that the probability distri-bution of the number of toys played with is as fol-lows:

Number of toys xi 0 1 2 3 4 5Probability pi 0 � 03 0 � 16 0 � 30 0 � 23 0 � 17 0 � 11

(a) Calculate the mean of X. Enter answer with 2digits after the decimal point.answer:

(b) Calculate the standard deviation of X. Enter an-swer with 4 digits after the decimal point.answer:

17.(1 pt) Laboratory data show that the time re-quired to complete two chemical reactions in a pro-duction process varies. The first reaction has a meantime of 40 minutes and a standard deviation of 2 min-utes; the second has a mean time of 25 minutes and a

standard deviation of 1 minute. The two reactions arerun in a sequence during production. There is a fixedperiod of 5 minutes between them as the product ofthe first reaction is pumped into the vessel where thesecond reaction will take place.

(a) What is the mean required for the entire pro-cess?answer:

18.(1 pt) Choose an American farm at random andmeasure its size in acres. Here are the probabilitiesthat the farm chosen falls in several acreage cate-gories:

Acres � 10 10 � 49 50 � 99 100 � 79 180 � 499 500 999 1000 1999 2000Probabillity 0 � 09 0 � 20 0 � 15 0 � 16 0 � 22 0 09 0 05 0 04

Let A be the event that the farm is less than 50acres in size, and let B be the event that it is 500 acresor more.

(a) Find P � A � .answer:

(b) Find P � B �answer:

(c) Find P � Ac � by the complement rule.answer:

(d) Find P � A � B � by the addition rule.answer:


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1.(1 pt) For each of the following situations, indi-cate whether a binomial distribution is a reasonableprobability model for the random variable X. AnswerYES or NO for each question.

(a) You observe the sex of the next 50 children bornat a local hospital; X is the number of girls amongthem. Assume that there are no twins or other multi-ple births among these births.answer:

(b) A couple decides to continue to have childreduntil their first girl is born; X is the total number ofchildren the couple has.answer:

(c) You want to know what percent of married peo-ple believe that mothers of young children should notbe employed outside the home. You plan to interview50 people, and for the sake of convenience you de-cide to interview both the husband and the wife in25 married couples. The random variable X is thenumber among the 50 persons interviewed who thinkmothers should not be employed.answer:

2.(1 pt) According to government data, 25% of em-ployed women have never been married.

(a) If 10 employed women are selected at random,what is the probability that exactly 2 have never beenmarried? (Use Table C). Give answer with 4 deci-mals.

answer:(b) What is the probability that 2 or fewer have

never been married?answer:(c) What is the probability that at least 8 have been

married?answer:

3.(1 pt) A believer in the ”random walk” theory ofthe behavior of stock prices thinks that an index ofstock prices has probability 0.65 of increasing in anyyear. Moreover, the change in the index in any givenyear is not influenced by whether it rose or fell in ear-lier years. Let X be the number of years among thenext 6 years in which the index rises.

(a) What are n and p in the binomial distribution ofX?

n =p =(b) Give the possible values that X can take and

the probability of each value.Fill in the values in thecorresponding cells of the table below.

XpX

(c) Find the mean of the number X of years inwhich the stock price index rises.

answer:(d) Find the standard deviation of X. Give answer

with 4 digits after the decimal point.Standard Deviation =e) What is the probability that X takes a value

within one standard deviation of its mean?answer:

4.(1 pt) A study by a federal agency concludes thatpolygraph (lie detector) tests given to truthful personshave probability about 0.2 of suggesting that the per-son is deceptive.

(a)A firm asks 12 job applicants about thefts fromprevious employers, using a polygraph to assess theirtruthfulness. Suppose that all 12 answer truthfully.

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What is the probability that the polygraph says atleast 1 is deceptive?

answer:(b) What is the mean number among 12 truthful

persons who will be classified as deceptive?answer:What is the standard deviation of this number? En-

ter answer with 4 digits after the decimal point.answer:(c) What is the probability that the number classi-

fied as deceptive is less than the mean?answer:

5.(1 pt) One way to check the effect of undercov-erage, nonresponse, and other sources of error in asample survey is to compare the sample with knowndemographic facts about the population. About 12percent of American adults are black. The number Xof blacks in a random sample of 1500 adults shouldtherefore vary with the B(1500, 0.12) distribution.

(a) What are the mean and standard deviation ofX?

mean:standard deviation:(b) Use the normal approximation to find the prob-

ability that the sample will contain 170 or fewerblacks. Be sure to check that you can safely use theapproximation.

answer:answer (with continuity correction) :

6.(1 pt) A selective college would like to have anentering class of 1200 students. Because not all stu-dents who are offered admission accept, the collegeadmits more than 1200 students. Past experienceshows that about 70% of the students will accept. Thecollege decides to admit 1500 students. Assumingthat students make their decisions independently, thenumber who accept has the B(1500, 0.7) distribution.If this number is less than 1200, the college will ad-mit students from its waiting list.

(a) What are the mean and standard deviation ofthe number X of students who accept?

mean:standard deviation:(b) Use the normal approximation to find the prob-

ability that at least 1000 students accept.answer:

answer (with continuity correction):(c) If the college decides to increase the number of

admission offers to 1700, what is the probability thatmore than 1200 will accept?

answer:

7.(1 pt) Here is a simple probability model formultiple-choice tests. Suppose that each student hasprobability p of correctly answering a question cho-sen at random from a universe of possible questions.(A strong student has a higher p than a weak student).The correctness of answers to defferent questions areindependent. Jodi is a good student for whom p =0.75.

(a) Use the normal approximation to find the prob-ability that Jodi scores 70 % or lower on a 100-question test.

answer:answer (with continuity correction):(b) If the test contains 250 questions, what is the

probability that Jodi will score 70% or lower?answer:answer (with continuity correction):(c) How many questions must the test contain in

order to reduce the standard deviation of Jodi’s pro-portion of correct answers to half its value for a 100-item test?

answer:(d) Laura is a weaker student for whom p=0.6.

Does the answer you gave in (c) for the standard de-viation of Jodi’s score apply to Laura’s standard de-viation also? (ANSWER YES OR NO).

answer :

8.(1 pt) The scores of students on the ACT collegeentrance examination in a recent year had the normaldistribution with µ � 18 � 6 and σ � 5 � 9.

(a) What is the probability that a single student ran-domly chosen from all those taking the test scores 21or higher?

answer:(b) Now take an SRS of 50 students who took the

test. What are the mean and standard deviation of thesample mean score of these 50 students?

mean:standard deviation:(c) What is the probability that the mean score of

these students is 21 or higher?2

answer: percent

9.(1 pt) A laboratory weighs filters from a coalmine to measure the amount of dust in the mine at-mosphere. Repeated measurements of the weight ofdust on the same filter vary normally with standarddeviation 0.08 milligram (mg) because the weighingis not perfectly precise. The dust on a particular fil-ter actually weighs 123 mg. Repeated weighings willthen have the normal distribution with mean 123 mgand standard deviation 0.08 mg.

(a) The laboratory reports the mean of 3 weighings.What is the distribution of this mean?

Is it normal? (YES/NO)mean:standard deviation:(b) What is the probability that the laboratory re-

ports a weight of 124 mg or higher for this filter?Hint: If the z-score that you calculate is greater

than the maximum table value in absolute value, thenyou may consider that the probability you calculatebased on that z-score is zero.

answer:

10.(1 pt) A company that owns and services a fleetof cars for its sales force has found that the servicelifetime of disc brake pads varies from car to car ac-cording to a normal distribution with mean 55,000miles and standard deviation 4500 miles. The com-pany installs a new brand of brake pads on 8 cars.

(a) If the new brand has the same lifetime distribu-tion as the previous type, what is the distribution ofthe sample mean lifetime for the 8 cars?

answer (enter the type of distribution, without writ-ing the word ”distribution”):

mean:standard deviation:(b) The average lifetime of the pads on these cars

turns out to be 51,800 miles. What is the probabil-ity that the sample mean lifetime is 51,800 miles orless if the lifetime distribution is unchanged? Thecompany takes this probability as evidence that theaverage lifetime of the new brand of pads is less than55,000 miles.

answer:

11.(1 pt) Children in kindergarten are sometimesgiven the Ravin Progressive Matrices Test (RPMT)to assess their readiness for learning. Experience

at Southwark Elementary School suggests that theRPMT scores for its kindergarten pupils have mean13.6 and standard deviation 3.1. The distribution isclose to normal. M.̊ Lavin has 22 children in hiskindergarten class this year. He suspects that theirRPMT scores will be unusually low because the testwas interrupted by a fire drill. To check the suspicion,he wants to find the level L such that there is proba-bility only 0.05 that the mean score of 22 childrenfalls below L when the usual Southwark distributionremains true.

What is the value of L? Enter answer with 3 digitsafter the decimal point.

L =

12.(1 pt) An experiment on the teaching of readingcompares two methods, A and B. The response vari-able is the Degree of Reading Power (DRP) score.The experimenter uses Method A in a class of 26 stu-dents and Method B in a comparable class of 24 stu-dents. The classes are assigned to the teaching meth-ods at random. Suppose that in the population of allchildren of this age the DRP score has the N(34, 12)distribution if Method A is used and the N(37, 11)distribution if Method B is used.

(a) What is the distribution of the mean DRP scorefor the 26 students in the A group? (Assume that thisgroup can be regarded as an SRS from the populationof all children of this age.)

type of distribution:mean:standard deviation:(b) What is the distribution of the mean score for

the 24 students in the B group?type of distribution:mean:standard deviation:(c) Use the results of (a) and (b), keeping in mind

that the means of the two groups A and B are inde-pendent, to find the distribution of the difference be-tween the mean scores in the two groups.

type of distribution:mean:standard deviation:(d) What is the probability that the mean score for

the B group will be at least 4 points higher than themean score for the A group?

3

answer:13.(1 pt) The study habits portion of the Survey

of Study Habits and Attitudes (SSHA) psychology-cal test consists of two sets of questions. One setmeasures ”delay avoidance” and the other measures”work methods”. A subject’s study habits score is thesum of X + Y of the delay avoidance score X and thework score Y. The distribution of X in a broad popula-tion of first-year college students is close to N(25,10),while the distribution of y in the same population isclose to N(25, 9).

(a) If a subject’s X and Y scores were independent,what would be the distribution of the study habitsscore X + Y?

distribution:mean:standard deviation:(b) Using the distribution you found in (a), what

proportion of the population have a study habits scoreof 60 or higher?

answer:(c) In fact, the X and Y scores are strongly corre-

lated. In this case, does the mean of X + Y still havethe value found in (a)?

answer (YES/NO):Does the standard deviation still have the value you

found in (a)?answer (YES/NO):

14.(1 pt) A study of working couples measures theincome X of the husband and the income Y of thewife in a large number of couples in which both part-ners are employed. Suppose that you knew the meansand the variances of both variables in the population.

(a) Is it reasonable to take the mean of the totalincome X + Y to be µX + µY ?

answer (YES/NO):(b) Is it reasonable to take the variance of the total

income X + Y to be σ2X + σ2

Y ?answer (YES/NO):


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WeBWorK demonstration assignmentThe main purpose of this WeBWorK set is to fa-

miliarize yourself with WeBWorK.Here are some hints on how to use WeBWorK ef-

fectively:� After first logging into WeBWorK change

your password.� Find out how to print a hard copy on the com-puter system that you are going to use. Printa hard copy of this assignment.� Get to work on this set right away and answerthese questions well before the deadline. Notonly will this give you the chance to figureout what’s wrong if an answer is not accepted,you also will avoid the likely rush and con-gestion prior to the deadline.� The primary purpose of the WeBWorK as-signments in this class is to give you the op-portunity to learn by having instant feedbackon your active solution of relevant problems.Make the best of it!

1.(1 pt) Starting salaries of 60 college graduateswho have taken a statistics course have a mean of$42,381 and a standard deviation of $10,404.Using a 0.98 degree of confidence, find both of thefollowing:

A. The margin of error E

B. The conficence interval for the mean µ:� µ �

2.(1 pt) A random sample of 90 observations pro-duced a mean of x � 21 and a standard deviationx � 4 � 64.

(a) Find a 99% confidence interval for µ�µ�

(b) Find a 95% confidence interval for µ�µ�

(c) Find a 90% confidence interval for µ�µ�

3.(1 pt) A test for the level of potasium in the bloodis not perfectly precise. Moreover, the actual level ofpotasium in a person’s blood varies slightly from dayto day. Suppose that repeated measurements for thesame person on different days vary normally with a

standard deviation of 0.2. Answer to the followingquestions writing the results with three digits after thedecimal point.a) Julie’s potassium level is measured once. The re-sult is x=3.4. Give a 90 percent confidence intervalfor her mean potassium level.

� µ �b)If three measurements were taken on different

days and the mean result is 3.4, what is a 90 percentconfidence interval for Julie’s mean blood potassiumlevel?

� µ �

4.(1 pt) Here are the Degree of Reading Power(DRP) scores for a sample of 44 third-grade students.

40 26 39 14 42 18 25 43 46 27 1947 19 26 35 34 15 44 40 38 31 4652 25 35 35 33 29 34 41 49 28 5247 35 48 22 33 41 51 27 14 54 45Suppose that the standard deviation of the popula-

tion of DRP scores is known to be 11. Give a 95%confidence interval for the population mean score.Enter answer with 2 digits after the decimal point.

� µ �

5.(1 pt) Researchers planning a study of the read-ing ability of third-grade children want to obtaina 95% confidence interval for the population meanscore on a reading test, with margin of error nogreater than 3 points. They carry out a small pilotstudy to estimate the variability of test scores. Thesample standard deviation is 12 points in the pilotstudy, so in preliminary calculations the researcherstake the population standard deviation to be 12.

a) The study budget will allow as many as 100students. Calculate the margin of error to the 95%confidence interval for the population mean based onn=100.Enter answer with three digits after the deci-mal point.

Margin of error =b) There are many other demands on the research

budget. If all of these demands were met, there wouldbe funds to measure only 10 children. What is themargin of error of the confidence interval based onn=10 measurements? Enter answer with three digitsafter the decimal point.

Margin of error =1

c) Find the smallest value of n that would satisfythe goal of a 95% confidence interval with a marginof error 3 or less. Round up the result to the nextinteger.

Smallest n =6.(1 pt) Golf-course designers have become con-

cerned that old courses are becoming obsolete sincenew technology has given golfers the ability to hit theball so far. Designers, therefore, have proposed thatnew golf courses need to be built so that an averagegolfer can be expected to hit the ball more than 235yards on average. Suppose a random sample of 197golfers be chosen so that their mean driving distanceis 234.2 yards, with a standard deviation of 49.9.

Conduct a hypothesis test where H0 : µ�

235 andH1 : µ � 235 by computing the following:(a) test statistic(b) p-value p �(c) If this was a two-tailed test, then the p-value is

7.(1 pt) 40 people are randomly selected and theaccuracy of their wristwatches is checked, with posi-tive errors representing watches that are ahead of thecorrect time and negative errors representing watchesthat are behind the correct time. The 40 values havea mean of 118sec and a standard deviation of 163sec.Use a 0 � 01 significance level to test the claim that thepopulation of all watches has a mean of 0sec.

The test statistic isThe P-Value isThe final conclustion is� A. There is not sufficient evidence to warrant

rejection of the claim that the mean is equalto 0� B. There is sufficient evidence to warrant re-jection of the claim that the mean is equal to0

8.(1 pt) Which of the following questions does atest of significance answer?(answer by ”yes” or ”no”without quotations)

(a) Is the sample properly designed?answer:

(b) Is the observed effect due to chance?answer:

(c) Is the observed effect important?answer:

9.(1 pt) Every user of statistics should understandthe distinction between statistical significance andpractical importance. A sufficiently large sample willdeclare very small effects statistically significant. Letus suppose that SAT mathematics (SAT-M) scores inthe absence of coaching vary normally with mean475 and standard deviation 100. Suppose further thatcoaching may change the mean but does not changethe standard deviation. An increase in the SAT-Mscore from 475 to 478 is of no importance in seek-ing admission to college, but this unimportant changecan be statistically very significant. To see this, cal-culate the P-value for the test of (give answer with 4decimals)

H0 : µ � 475 � H1 : µ � 475.(a) A coaching service coaches 100 students; their

SAT-M scores average 478.answer:

(b) By the next year, the service has coached 1000students; their SAT-M scores average 478.answer:

(c) An advertising campaign brings the number ofstudents coached to 10,000; their average score is still478.answer:

10.(1 pt) The Survey of Study Habits and Attitudes(SSHA) is a psychological test that measures the mo-tivation, attitude toward school, and study habits ofstudents. Scores range from 0 to 200. The meanscore for U.S. college students is about 115, and thestandard deviation is about 30. A teacher who sus-pects that older students have better attitudes towardschool gives the SSHA to 20 students who are at least30 years of age. Their mean score is x � 135 � 2.

a) Assuming that σ � 30 for the population of olderstudents, carry out a test of H0 : µ � 115 � Ha : µ � 115.

Report the P-value of your test.z test statistic =P-value =Do you reject H0? Answer YES or NO:

11.(1 pt) The mean yield of corn in the UnitedStates is about 120 bushels per acre. A survey of40 farmers this year gives a sample mean yield ofx � 123 � 8 bushels per acre. We want to know whetherthis is good evidence that the national mean this year

2

is not 120 bushels per acre. Assume that the farm-ers surveyed are an SRS from the population of allcommercial corn growers and the standard deviationof the yield in this population is σ � 10 bushels peracre. Give the P-value for the test of H0 : µ � 120 �Ha : µ �� 120.

z test statistic =P-value =Are you convinced that the population mean is not

120 bushels per acre?Answer YES or NO:12.(1 pt) The level of calcium in the blood in

healthy young adults varies with mean about 9.5 mil-ligrams per deciliter and standard deviation about σ=0.4. A clinic in rural Guatemala measures the bloodcalcium level of 180 healthy pregnant women at theirfirst visit for prenatal care. The mean is x � 9.58.

Is this an indication that the mean calcium level inthe population from which these women come differsfrom 0.95?

a) Give the P-value for this test.z test statistic =P-value =Is this strong evidence that the mean calcium level

of the population is different from 9.5 mg/dl?Answer YES or NO:b) Give a 95% confidence interval for the mean cal-

cium level µ in this population. We are confident thatµ lies quite close to 9.5. This illustrates the fact that atest based on a large sample (n = 180 here) will oftendeclare even a small deviation from H0 to be statisti-cally significant.

Answer:�

µ�


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1.(1 pt) What critical value t* from Table D in yourtextbook should be used for a confidence interval forthe mean of the population in each of the followingsituations?

(a) A 90% confidence interval based on n = 12 ob-servations.

degrees of freedom (df)=t* =(b) A 95% confidence interval from an SRS of 30

observations.degrees of freedom (df)=t* =(c) A 80% confidence interval from a sample size

of 18.degrees of freedom (df)=t* =

2.(1 pt) The one-sample t statistic for testing H0 :µ � 0 � Ha : µ �� 0 from a sample of n = 15 observationshas the value t = 1.97.

(a) What are the degrees of freedom for this statis-tic?

degrees of freedom (df)=

(b) Give the two critical values t* from Table D inyour textbook that bracket t.

t1 =t2 =(c) What are the right-tail probabilities p for these

two entries?p1 =p2 =(d) Between what two values does the P-value of

the test fall (write first the smaller p-value and thenthe larger one)?

P-value (1) =P-value (2) =(e) Is the value t = 1.97 significant at 5% level?answer (YES/NO) =Is it significant at the 1% level? answer (YES/NO)

=3.(1 pt) The one-sample t statistic for testing H0 :

µ � 20 � Ha : µ �� 20 based on n = 12 observations hasthe value t = -2.45.

(a) What are the degrees of freedom for this statis-tic?

degrees of freedom (df)=(b) How would you report the P-value based on Ta-

ble D in your textbook?¡ P ¡

4.(1 pt) The level of various substances in theblood of kidney dialysis patients is of concern be-cause kidney failure and dialysis can lead to nutri-tional problems. A researcher performed blood testson several dialysis patients on six consecutive clinicvisits. One variable measured was the level of phos-phate in the blood. Phosphate levels for an individualtend to vary normally over time. The data on one pa-tient, in milligrams of phosphate per deciliter (mg/dl)of blood, are given below.

5.6 ; 5.1 ; 4.6 ; 4.8 ; 5.7 ; 6.4(a) Calculate the sample mean and its standard er-

ror.mean =standard error =(b) Use the t procedures to give a 90% confidence

interval for the mean phosphate level of this patient.degrees of freedom =t* =

¡ µ ¡

1

5.(1 pt) Test the claim that the two samples de-scribed below come from populations with the samemean. Assume that the samples are independentsimple random samples. Use a signifcance level ofα � 0 � 05Sample 1: n1 � 19 � x1 � 29 � 3 � s1 � 7 � 12Sample 2: n2 � 15 � x2 � 21 � 2 � s2 � 8 � 55(a) The degree of freedom is(b) The test statistic is(c) Determine based on Table D the two probabili-ties that border the P-value:

� P � value �The final conclustion is

� A. There is not sufficient evidence to rejectthe null hypothesis that � µ1 � µ2 �� 0.� B. We can reject the null hypothesis that� µ1 � µ2 �� 0 and accept that � µ1 � µ2 �� 0.

6.(1 pt) In a study of heart surgery, one issue wasthe effect of drugs called beta-blockers on the pulserate of patients during surgery. The available sub-jects were divided at random into two groups of 30

patients each. One group received a beta-blocker; theother group, a placebo. The pulse rate of each patientat a critical point during the operation was recorded.The treatment group had mean 65.2 and a standarddeviation 7.8. For the control group, the mean was70.3 and the standard deviation 8.3.

(a) Do beta-blockers reduce the pulse rate? Testthe null hypothesis H0 : µ1 � µ2 versus the alternativehypothesis Ha : µ1 � µ2. Do a t test and state yourresults:

degrees of freedom =t test statistic =

¡ P � value ¡Is the result significant at the 5% level? answer:Is the result significant at the 1% level? answer:(b) Give a 99% interval for the difference in mean

pulse rate.degrees of freedom =t � =

¡ µ ¡


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Math 1010-70 Summer 2002

WeBWorK Questionnaire

Tom Robbins

due 8/15/02 at 7:00 AMWe are very interested in your opinion about WeBWorK, and we appreciate your willingness to complete

this questionnaire. The information you provide will not be traced back to you, and will be used excl;usivelyto evaluate and improve our WeBWorK services. Thank you for your time!

1.(0 pts) Dear Students,We would very much appreciate your help in evaluating WeBWorK. We would like to hear about both thestrengths and weaknesses of WeBWorK as you see them and any suggestions that you have for improving theprogram or the way it is used. WeBWorK has already benefited from past comments by students and we wantto continue to improve it and make it as useful as possible as an educational tool.All questions are optional, but we appreciate all the information you give us. Thank you very much for yourtime.

Please select the best choice for each question.

A. For which mathematics course are you filling out this questionnaire?

A. � Math 1010B.� Math 1030C.� Math 1050D.� Math 1060E.� Math 1070F.� Math 1090

G.� Math 1100H.� Math 1210I.� Math 1220J.� Math 2210

K.� Other (please specify)1

B. What is your gender?

A. � FemaleB.� Male

C. Is this your first time taking this course?

A. � YesB.� No

D. What was the most recent previous math course, if any, that you were enrolled in at this university?

A. � Math 1010B.� Math 1030C.� Math 1050D.� Math 1060E.� Math 1070F.� Math 1090

G.� Math 1100H.� Math 1210I.� Math 1220J.� none

K.� Other (please specify)

E. What was the content of your most recent high school math course?

A. � CalculusB.� Pre-CalculusC.� AlgebraD.� GeometryE.

2

� Other (please specify)

F. What is your ethnicity?

A. � Asian American/Pacific IslanderB.� Black/African AmericanC.� Caucasian/WhiteD.� Latino/Hispanic AmericanE.� Native American/Alaskan NativeF.� Other (please specify)

G. What is your academic status?

A. � FreshmanB.� SophomoreC.� JuniorD.� SeniorE.� Other (please specify)

H. What is your intended major?

A. � Social Sciences (i.e. Psychology, Ecomonics, Political Science, History, etc.)B.� Humanities (i.e. English, Religion and Classics, Languages, etc.)C.� Natural Sciences (i.e. Physics, Chemistry, Biology, etc.)D.� EngineeringE.� MathematicsF.� Other (please specify)

I. Do you plan to enroll in other mathematics courses at this university?

A. � Yes3

B.� No

J. What grade do you expect to receive for this class?

A. � AB.� BC.� CD.� DE.� E

K. Approximately how many days before weekly due dates do you typically begin to work on WeBWorKassignments?

A. � 1B.� 2C.� 3D.� 4E.� Other (please specify)

L. How many hours per week do you typically spend on WeBWorK problem sets?

A. � Less than 1 hourB.� 1 hourC.� 2 hoursD.� 3 hoursE.� More than 3 hours

M. How would you rank yourself as a mathematics student?

A. � Among the bestB.� Above averageC.� AverageD.

4

� Below averageE.� Among the worst

N. Have you used weBWorK in courses previous to this one?

A. � YesB.� No

O. Do you have access to a computer in your dorm room or residence?

A. � YesB.� No

P. Where do you typically work on WeBWorK problem sets?

A. � Your dorm roomB.� Your off campus residenceC.� A campus computing facilityD.� The mathematics departmentE.� The libraryF.� Other (please specify)

Please rate the frequency with which you do each of the following:¡TABLE BORDER CELLSPACING=1 CELLPADDING=4 WIDTH=600¿ ¡TR¿¡TD COLSPAN=”2” VALIGN=”TOP”

¿Scale: 5 all the time, 4 almost all the time, 3 sometimes, 2 almost never, 1 never, 0 no answer¡/TD¿ ¡/TR¿¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”451. Use the email connection to get help with specific problems ¡/TD¿¡/TR¿¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3

5

� 4� 5

¡/TD¿ ¡TD WIDTH=”452. Do WeBWorK assignments with other students ¡/TD¿ ¡/TR¿ ¡TR¿¡TD WIDTH=”55

� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”453. Get an entire assignment correct ¡/TD¿ ¡/TR¿¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”454. Seek help from your teaching assistant ¡/TD¿ ¡/TR¿¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”455. Seek help from your instructor ¡/TD¿ ¡/TR¿¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”456. Guess at problems you don’t understand ¡/TD¿ ¡/TR¿¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”457. Get frustrated with and give up on a particular problem due to mathematicaldifficulty ¡/TD¿ ¡/TR¿

6

¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”458. Get frustrated with the time it takes WeBWorK to respond to answers you submitto it ¡/TD¿ ¡/TR¿

¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”459. Get frustrated with the syntactic requirements of answers you submit to WeBWorK¡/TD¿ ¡/TR¿

¡/TABLE¿Please rate the extent to which you agree with each of the following statements:¡TABLE BORDER CELLSPACING=1 CELLPADDING=4 WIDTH=600¿ ¡TR¿¡TD COLSPAN=”2” VALIGN=”TOP”

¿ 5 strongly agree, 4 agree, 3 neutral, 2 disagree, 1 strongly disagree, 0 no answer¡/TD¿ ¡/TR¿¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”4510. I prefer WeBWorK over paper and pencil homework ¡/TD¿¡/TR¿¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH=”4511. WeBWorK problems are challenging ¡/TD¿ ¡/TR¿ ¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

7

¡/TD¿ ¡TD WIDTH= ”4512. Class lectures effectively prepare me to complete WeBWorK assignments ¡/TD¿¡/TR¿

¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”4513. The content of WeBWorK problems is consistent with the material taught inlectures ¡/TD¿ ¡/TR¿

¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”4514. The content of WeBWorK problems is consistent with the material tested onexams ¡/TD¿ ¡/TR¿

¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”4515. WeBWorK effectively prepares me for course examinations ¡/TD¿ ¡/TR¿¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”4516. The immediate responses I get from WeBWorK make me more persistent withassignments ¡/TD¿ ¡/TR¿

¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

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¡/TD¿ ¡TD WIDTH= ”4517. The immediate responses I get from WeBWorK help me learn the course material¡/TD¿ ¡/TR¿

¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”4518. Email access to professors is a useful component of WeBWorK ¡/TD¿ ¡/TR¿¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”4519. The Email feedback mechanism has made it easy to communicate with myprofessor ¡/TD¿ ¡/TR¿

¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”4520. I can successfully access WeBWorK whenever I need to ¡/TD¿ ¡/TR¿ ¡TR¿¡TDWIDTH= ”55

� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”4521. I know where to go to get help when I am having trouble with course material orWeBWorK problems ¡/TD¿ ¡/TR¿

¡TR¿¡TD WIDTH= ”55� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”4522. WeBWorK makes mathematics courses more enjoyable ¡/TD¿ ¡/TR¿ ¡/TABLE¿9

Please rate your satisfaction with each of the following:¡TABLE BORDER CELLSPACING=1 CELLPADDING=4 WIDTH=600¿ ¡TR¿¡TD COLSPAN=”2” VALIGN=”TOP”

¿ 5 highly satisfied, 4 satisfied, 3 neutral, 2 dissatisfied, 1 strongly dissatisfied, 0 no answer¡/TD¿ ¡/TR¿¡TR¿¡TD WIDTH= ”55

� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”4523. Your course instructor ¡/TD¿¡/TR¿¡TR¿¡TD WIDTH= ”55

� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH=”4524. Your course TA ¡/TD¿ ¡/TR¿ ¡TR¿¡TD WIDTH= ”55

� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”4525. Your course ¡/TD¿ ¡/TR¿¡TR¿¡TD WIDTH= ”55

� 0� 1� 2� 3� 4� 5

¡/TD¿ ¡TD WIDTH= ”4526. WeBWorK ¡/TD¿ ¡/TR¿¡/TABLE¿27. Please tell us what you like about WeBWorK.

28. Please tell us what you do not like about WeBWorK10

29. Please use this space for additional comments regarding WeBWorK

Thank you very much.


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WeBWorK demonstration assignment - Math...70After ﬁrst logging into WeBWorK change your password....

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