Statistics for the Behavioral and Social...

Test Bank to Accompany

Statistics for the Behavioral and Social Sciences

Fifth Edition

by

Aron/Coups/Aron

Prentice Hall

Contents

Chapter 1 Displaying the Order in a Group of Numbers Using Tables and Graphs 1

Chapter 2 The Mean, Variance, Standard Deviation, and Z Scores 20

Chapter 3 Correlation and Prediction 38

Chapter 4 Some Key Ingredients for Inferential Statistics: The Normal Curve, Sample versus Population, and Probability 63

Chapter 5 Introduction to Hypothesis Testing 78

Chapter 6 Hypothesis Tests with Means of Samples 99

Chapter 7 Making Sense of Statistical Significance: Effect Size and Statistical Power 118

Chapter 8 Introduction to the t Test: Single Sample and Dependent Means 136

Chapter 9 The t Test for Independent Means 165

Chapter 10 Introduction to the Analysis of Variance 191

Chapter 11 Chi-Square Tests and Strategies When Population Distributions Are Not Normal 226

Chapter 12 Applying Statistical Methods In Your Own Research Project 259

Copyright © 2011 Pearson Education, Inc. All rights reserved. 1

Chapter 1 Displaying the Order in a Group of Numbers Using Tables and Graphs

1) An education researcher collects data on how many students are on scholarship at various local colleges. The researcher then makes a frequency table to summarize the data. The researcher is using a(n):

A) measure of central tendency

B) descriptive statistical method

C) intuitive statistical method

D) inferential statistical method

Answer: B

2) A student theorizes that performance on a statistics exam will be related to the number of hours she spent studying. This student will be required to use __________ to test her theory.

A) common sense

B) reasoning by analogy

C) inferential statistics

D) intuition

Answer: C

3) The two main branches of statistical methods are:

A) theoretical and inferential

B) intuitive and observational

C) descriptive and intuitive

D) descriptive and inferential

Answer: D

4) The value of putting numbers into a frequency table is that:

A) it makes the pattern of numbers clear at a glance

B) it enables you to draw inferences from the table

C) frequency tables are required by many journals

D) all of the above

Answer: A


5) A psychologist is interested in studying aggressive tendencies in people and develops a measure of this personality characteristic. Aggression has become a(n) __________ in the psychologist’s study.

A) abstract concept

B) variable

C) value

D) invariable construct

Answer: B

6) Several employees of a major corporation are rated for their degree of job satisfaction. If a particular employee’s job satisfaction is rated 8 on a 20-point scale, 8 represents that employee’s:

A) frequency

B) variable

C) score

D) percentile

Answer: C

7) An intelligence test includes 15 items. Thus, a person could get any number correct between 0 and 15. Each of these numbers correct (0–15) that a person could possibly get is called a:

A) value

B) variable

C) frequency

D) mean

Answer: A

8) The difference between scores of 3 and 4 is approximately the same as the difference between scores of 15 and 16, the type of variable known as:

A) equal interval

B) differential

C) nondifferential

D) rank-order

Answer: A


9) Numeric variables are also called:

A) nominal variables

B) categorical variables

C) quantitative variables

D) irrelevant variables

Answer: C

10) All of the following are examples of rank-order variables EXCEPT:

A) a student’s rank in his or her graduating class

B) a tennis player’s standing compared to other athletes in the region

C) a runner’s place finished in a race

D) a student’s level of stress just before an exam

Answer: D

11) Which of the following is NOT an example of a nominal variable?

A) Hair color

B) Religious affiliation

C) Social Security number

D) Score on an IQ test

Answer: D

12) Which of the following is an example of a nominal variable?

A) Grade point average (3.2, 2.7, etc.)

B) Number of friends a person has (0, 1, etc.)

C) Birth position in a family (first, second, etc.)

D) Nationality of the car a person owns (American, Japanese, etc.)

Answer: D

13) Which of the following is an example of an equal-interval variable?

A) Marital status of a person (single, divorced, etc.)

B) Number of friends a person has (2, 4, etc.)

C) Results of a horse race (arrived 1st, 2nd, etc.)

D) Numbers printed on the back of a basketball team’s jerseys (21, 43, etc.)

Answer: B


14) A researcher wishing to summarize all the scores for a variable in a study creates a frequency table, but finds that there are so many values that the table is too cumbersome to be useful. The next step would be to make a:

A) histogram

B) frequency polygon

C) grouped frequency table

D) pie chart

Answer: C

15) A researcher measures the eye movements of 100 participants as they read ambiguous words embedded within sentences. Because eye movements are measured in milliseconds, and there are likely to be many different times measured, the researcher decides to use a __________ to help make sense of these data.

A) frequency polygraph

B) scatterplot

C) grouped frequency table

D) horizontal bar chart

Answer: C

16) When making a frequency table for a numeric variable, the list down the left edge of the page should include:

A) all possible values, starting from the highest and ending with the lowest

B) only even-numbered values

C) only odd-numbered values

D) the cumulative frequencies and percentages for female participants

Answer: A

17) When making a frequency table for a nominal variable, the values listed on the left-hand side of the frequency table should be:

A) the percent correct

B) the number of social interactions per week

C) the categories of the variable

D) the appropriate interval groupings

Answer: C


18) A frequency table lists:

A) the times per second that variations occur in various wave bands

B) the number of scores at each value

C) the intensity of a variable over all the participants studied

D) the average and median values of each variable

Answer: B

19) A frequency table includes columns for all of the following EXCEPT:

A) the number of ratings for each value on a scale

B) the frequency of scores at each value

C) the percentage of scores for each value

D) the standard deviation of the measurement scale

Answer: D

20) The word “frequency” in a frequency table refers to:

A) cycles per second

B) the number of scores at each value of a variable

C) the times per unit change of each score

D) the cumulative percentage for any given value

Answer: B

21) Consider the scores 1, 3, 3, 5, 6, 6, 6, 7, 7, 8. Which of the following would be the correct top line of a frequency table?

A) 3, 2, 20%

B) 10, 10, 100%

C) 0, 2, 25%

D) 8, 1, 10%

Answer: D

22) Consider the scores 2, 6, 7, 1, 7, 8, 5, 4. Which of the following would be the correct second line of the frequency table?

A) 2, 7, 20%

B) 7, 2, 25%

C) 6, 1, 6%

D) 1, 1, 12%

Answer: B


23) A histogram looks most like:

A) the skyline of a city

B) a large wave

C) a silhouette of mountains

D) a pattern of iron filings

Answer: A

24) A histogram is most closely related to which of the following?

A) Pie chart

B) Line plot

C) Contour plot

D) Bar chart

Answer: D

25) In a histogram, the vertical (up and down) dimension displays:

A) possible values the variable can have

B) intensity of the variable

C) mean score

D) frequency

Answer: D

26) In a histogram, the horizontal dimension displays a:

A) range of possible values the variable can have

B) percentile score for each individual

C) mean score

D) frequency

Answer: A

27) When working with a nominal variable, the histogram is called a(n):

A) bar graph

B) frequency polygon

C) area plot

D) bubble plot

Answer: A


28) When making a histogram, it is easiest if you begin with a:

A) list of all the scores in order

B) frequency table

C) list all of the percentages in order

D) normal curve table

Answer: B

29) An important difference between a histogram and a frequency polygon is that the frequency polygon:

A) is used for grouped values

B) begins and ends with a frequency of 10 (i.e., at the y-axis)

C) covers the full range of values (i.e., 0–100)

D) begins and ends with a frequency of zero (i.e., at the horizontal axis)

Answer: D

30) A frequency polygon looks most like:

A) the skyline of a city

B) a large wave

C) a silhouette of mountains

D) a series of intersecting shapes

Answer: C

31) Place the five steps for making a frequency polygon into the correct order: 1. Along the left side of the page (y-axis), make a scale of frequencies that ranges from 0 at

the bottom to the highest frequency for any value. 2. Connect the points with lines. 3. Make a frequency table. 4. Mark a point above each value with a height for the frequency of that value. 5. Put the values along the bottom of the page (x-axis).

A) 3, 5, 1, 4, 2

B) 2, 3, 1, 4, 5

C) 5, 3, 1, 2, 3

D) 3, 5, 1, 2, 4

Answer: A


32) Social scientists use frequency tables, histograms, or frequency polygons to show:

A) the relation between two variables

B) the reasoning behind experiments

C) specific hypotheses and test their validity

D) how the data they collect are distributed

Answer: D

33) Why might a frequency polygon include an extra value at the start and end along the bottom?

A) To illustrate the bimodal distribution of the data

B) To highlight the value with the largest frequency

C) To make a closed figure (i.e., polygon)

D) To construct a rectangular distribution

Answer: C

34) The distribution of scores in a research study in the behavioral and social sciences is usually:

A) unimodal

B) bimodal

C) multimodal

D) rectangular

Answer: A

35) A researcher rates participants’ empathic responses to the distress of strangers on a scale of 1 to 10. Most participants were rated either 3 or 7. How would this distribution be described?

A) Bimodal

B) Unimodal

C) Rectangular

D) Normal

Answer: A

36) If all the values in a distribution have about the same frequency, it is called a(n):

A) multimodal distribution

B) rectangular distribution

C) bimodal distribution

D) equalized distribution

Answer: B


37) On the first exam in an introductory statistics class most students did very well and only a few did poorly. How would you describe the distribution of test scores?

A) Symmetrical

B) Skewed to the left

C) Having a floor effect

D) Skewed to the right

Answer: B

38) On an exam in a cognitive psychology class, most students attained a perfect score. This is an example of:

A) a symmetrical distribution

B) a bimodal distribution

C) a ceiling effect

D) a floor effect

Answer: C

39) When a distribution is skewed to the right, it means that:

A) there are more scores piled up at the high end of the range

B) the scores are evenly distributed

C) there are more scores piled up at the low end of the range

D) there is a ceiling effect

Answer: C

40) When a distribution is skewed to the left, it is likely that:

A) there is a floor effect

B) there are more scores piled up at the low end of the range

C) the distribution is approximately normal and symmetrical

D) there is a ceiling effect

Answer: D

41) In some cases, researchers describe a distribution in terms of whether its tails have many or few scores in them. This aspect of the shape of a distribution is known as:

A) symmetry

B) kurtosis

C) z-transformation

D) queue

Answer: B


42) When a distribution is heavy-tailed it means that:

A) it has a flat appearance with many scores at the extremes (tails)

B) it is skewed to the right

C) it is skewed to the left

D) it has a pinched appearance with few scores at the extremes (tails)

Answer: A

43) A frequency table is most likely to be included in a research article when:

A) nominal variables are involved

B) there are a very small number of scores

C) a correlation is being reported

D) there are only two values for the variable

Answer: A

44) If you suffer from test anxiety, some useful advice is to:

A) overprepare for tests (at least at first)

B) learn methods to breathe properly and deeply

C) create a practice test situation that is similar to the real test

D) all of the above

Answer: D

45) Which of the following is supported by research cited in your text?

A) Women generally do worse in statistics classes because they have lower expectations for themselves.

B) Women tend to do worse in statistics because others have lower expectations of them.

C) Women tend to do worse in statistics because instructors generally call on them less often.

D) Women generally do as well as men in statistics classes.

Answer: D

46) Research by Wolf, Van Doorn, and Weissing (2008) indicates that high sensitivity, reactivity, or responsiveness:

A) are innate traits found in about 15–20% of humans

B) are related to a tendency to reflect before acting, rather than rushing into things

C) are related to a tendency to have strong emotional reactions to events

D) all of the above

Answer: D


47) According to your text, Hyde and Mertz (2009) found that the more gender equality that exits in a society, the more likely it is that women are equal to men in terms of math performance, and the greater likelihood that women have “profound mathematical talent.” (True or False).

Answer: TRUE

48) Match the term on the left with its correct definition on the right:

A) ceiling effect 1) distribution with many scores at each of the two extremes (tails)

B) heavy-tailed distribution 2) specific, mathematically defined, bell-shaped frequency distribution commonly observed in nature

C) light-tailed distribution 3) situation in which many scores pile up at the high end of a distribution (creation skewness to the left)

D) normal curve 4) distribution with few scores at each of the two extremes (tails)

Answer: A-3; B-1; C-4; D-2

Questions 49 and 50 refer to the table below.

49) According to the table, what is the most common types of cognitive problem faced by Alzheimer’s disease patients?

A) Motor problems

B) Language problems

C) Memory problems

D) Attentional problems

Answer: C

Incidence of Memory, Language, and Motors Deficits in Alzheimer’s Disease Patients (N = 200)

Cognitive Symptom N % Memory Problems Language Problems Motor Problems

180 64 40

90% 32% 20%


50) According to the table, what is the total number of patients in this sample who suffer from motor problems?

A) 20/200

B) 40

C) 40/N

D) 64

Answer: B

51) Social scientists use __________ to summarize and make understandable a group of numbers collected in a research study.

Answer: descriptive statistics

52) Researchers use __________ to draw statistical conclusions that go beyond the numbers actually collected in the research.

Answer: inferential statistics

53) A listing that shows how many times each value of a variable occurs among a particular group of scores is called a(n) __________.

Answer: frequency table

54) A test of social skills is administered to all professors at a local college. The __________ of a particular professor is 81.

Answer: score

55) In a study of hospitalized psychiatric patients, the __________ of interest is how well the patients can take care of their rooms, as rated by the nurses on a scale of 0 to 7.

Answer: variable

56) On a measure of social skills, the difference between scores of 6 and 7 has the same meaning as a difference between scores of 25 and 26. This measure is considered a(n) __________ variable.

Answer: equal-interval

57) Another name for an ordinal variable is a(n) __________ variable.

Answer: rank-order

58) Equal-interval and rank-order variables are both __________ variables.

Answer: numeric, quantitative


59) The type of transportation a person uses to get to work (e.g., car, bus) is an example of a(n) __________ variable.

Answer: nominal, categorical

60) When making a frequency table, the values are listed in the first column and the __________ for each value is listed in the second column.

Answer: frequency

61) The third column of a frequency table usually contains __________.

Answer: percentages, %

62) A business researcher set up a __________ that lists the number of employees for each level of earnings, from the level of $80,000–99,999, going down to the level of $20,000–29,999.

Answer: grouped frequency table

63) A way to simplify a frequency table when there are a large number of possible values is to group the scores into __________.

Answer: intervals

64) A frequency table, histogram, or frequency polygon describes a(n) __________.

Answer: frequency distribution, distribution of scores

65) A drawback associated with the use of grouped frequency tables is that you lose information about the breakdown of frequencies within each interval. (True or False)

Answer: TRUE

66) Frequency tables can be used for numerical but not nominal variables. (True or False)

Answer: FALSE

67) The histogram of a(n) __________ distribution has one of the bars higher than all the others.

Answer: unimodal

68) In a study of exercise behavior, a researcher found that the shape of the distribution of the number of hours exercised was __________ because one large group of people did not exercise at all while another large group all exercised approximately hours per week.

Answer: bimodal

69) The number of times the various numbers on a roulette wheel come up, in the long run, form a(n) __________ frequency distribution.

Answer: rectangular, symmetrical


70) A distribution is called __________ when the pattern of frequencies on the left and right side are mirror images of each other.

Answer: symmetrical

71) A distribution in which the scores pile up on one end and are spread out on the other end is an example of a(n) __________ distribution.

Answer: skewed

72) On a particular test of reading ability (in which high scores mean high reading ability), the distribution of adults is skewed to the __________ because most adults have fairly good reading ability, but a small number of people are nearly illiterate.

Answer: left

73) The distribution of data collected in behavioral and social science research studies often approximates a(n) __________.

Answer: normal curve

74) A rectangular distribution, in addition to being symmetrical, would be an example of a(n): __________.

Answer: heavy-tailed distribution

75) Explain the difference between descriptive and inferential statistical methods. Provide an example of how each of these methods might be used in a study examining the effects of a behavioral intervention for children with autism.

76) Explain why a grouped frequency table can sometimes be more useful than an ordinary frequency table for categorizing and displaying a group of numbers.

77) You are asked to develop a new measure of leadership ability to be used in a study of adolescent behavior (with male and female students in Grades 6–8). (a) What is the variable of interest in this study? (b) Is your variable equal-interval, rank-ordered, or nominal? (c) Describe the nature of your measure and its range of values. (d) Do you anticipate a normal distribution of scores on your variable? If not, what do you expect to find with regard to the shape of your distribution?

78) Explain what it means to have a ceiling effect in a distribution of scores. Provide an example.

79) Sketch the following: (a) a normal distribution, (b) a bimodal distribution, (c) a positively skewed distribution, and (d) a heavy-tailed distribution.

80) Make up an example of a distribution that would be much more peaked than usual.

81) Make up a study that would produce a distribution that is bimodal.


82) Make up a study that would produce a distribution that is rectangular.

83) A developmental psychologist studied how long it took toddlers to pick up a particular attractive new toy. Fifty toddlers were studied, all of whom eventually picked up the toy. In the research article, the psychologist provided the following table for the approximate number of minutes it took to lift the toy.

(a) Using this table as an example, explain the idea of a frequency table to a person who has never had a course in statistics.

(b) Explain the general meaning of the pattern of results (sketch a frequency graph if necessary).

84) An anthropologist examined the average number of children in a particular group of 84 hunter-gatherer societies. The anthropologist reported that the distribution was bimodal. Explain what this means to a person who has never had a course in statistics.

Minutes f % 10 7 14 9 0 0 8 3 6 7 5 10 6 7 14 5 8 16 4 9 18 3 7 14 2 2 4 1 1 2


85) A sociologist surveyed 16 single senior citizens living in private apartments. Each participant completed a questionnaire on the number of telephone conversations he or she had had in the last day. Their answers were as follows: 5, 0, 2, 1, 1, 9, 0, 1, 0, 3, 1, 1, 4, 3, 4, 7.

Construct a frequency table. Make a histogram based on the frequency table. Describe in words the shape of the histogram.

Answer: X f % 9 1 6.3 8 0 0.0 7 1 6.3 6 0 0.0 5 1 6.3 4 2 12.5 2 1 6.3 1 5 31.3 0 3 18.8

86) A researcher recorded the numbers of rule infractions for 12 prison inmates over a 6-month period and found them to be 1, 3, 0, 1, 0, 6, 8, 2, 0, 1, 0, 2.

Construct a frequency table. Make a histogram based on the frequency table. Describe in words the shape of the histogram.

Answer: X f % 8 1 8.3 7 0 0.0 6 1 8.3 5 0 0.0 4 0 0.0 3 1 8.3 2 2 16.7 1 3 25.0 0 4 33.3


87) A study recorded the number of units produced per hour by 15 factory workers. The results were as follows: 8, 10, 4, 9, 9, 10, 1, 9, 8, 5, 9, 9, 8, 7, 8.

Construct a frequency table. Make a frequency polygon based on the frequency table. Describe in words the shape of the frequency polygon.

Answer: X f % 10 2 13.3 9 5 33.3 8 4 26.7 7 1 6.7 6 0 0.0 5 1 6.7 4 1 6.7 3 0 0.0 2 0 0.0 1 1 6.7


88) A political scientist surveyed 20 active members of a small political action group about how many hours they spent on the group’s activities each week. The results were as follows: 24, 41, 1, 41, 14, 2, 40, 58, 2, 1, 41, 2, 41, 30, 0, 41, 3, 3, 41, 49.

Make a grouped frequency table using intervals from 0–9, 10–19, etc. Make a histogram based on the grouped frequency table. Describe in words the shape of the histogram.

Answer:

(example): Interval f % 50–59 1 5.0 40–49 8 40.0 30–39 1 5.0 20–29 1 5.0 10–19 1 5.0 0–9 8 40.0


89) On the first day of class, a statistics professor asks her students to report their eye color. These data are distributed as follows: green = 25 students, brown = 55 students, blue = 30 students, other = 6 students.

What is the variable of interest in this study? What type of variable is this? Construct a frequency table for these data. Sketch a bar graph for these data.

Answer: eye color nominal/categorical

Eye Color of Students

Color f % Green 25 21.5% Brown 55 47.5% Blue 30 26%

Other 6 5%


Chapter 2 The Mean, Variance, Standard Deviation, and Z Scores

1) The representative value of a group of scores refers to the middle of the group of scores. All of the following are types of representative values EXCEPT:

A) mean

B) metric

C) mode

D) median

Answer: B

2) A researcher observes the level of aggression of six 5-year-old boys over the course of a school day. The number of incidents for the group of boys was 2, 4, 6, 12, 8, 10. What is the mean number of aggressive acts for this group of children?

A) 4

B) 5

C) 7

D) 9

Answer: C

3) Five people’s scores on a survey of product recognition are 17, 12, 20, 13, 8. What is their mean score?

A) 12

B) 13

C) 14

D) 10

Answer: C

4) The ordinary average of a group of numbers is called the __________.

A) median

B) mean

C) standard deviation

D) mode

Answer: B


5) The rule for calculating the mean is to add up all the scores in a sample and divide by the __________.

A) median

B) number of scores minus 1

C) number of scores

D) most frequent score

Answer: C

6) Based on the scores 1, 9, 3, 6, 1, 2, 6, 2, 2, 8, a score of 4 is the __________.

A) mode

B) median

C) mean

D) standard deviation

Answer: C

7) In statistical formulas, what does N stand for?

A) The number of different values possible on the variable

B) The number of scores in a distribution

C) The normal curve

D) The normalized Z score in a distribution of scores

Answer: B

8) A research team studied the rate at which infants in the three different countries vocalized distress. Below are the scores from each country. Which group of infants showed the highest mean rate of distress vocalization over the 45-minute observation period?

Country A: 9, 9, 10, 13, 8, 8, 11, 11, 10, 7, 13, 6, 18, 9, 9, 12, 13, 10, 5, 14 Country B: 15, 15, 16, 19, 14, 14, 17, 17, 16, 13, 19, 12, 18, 10, 10, 15, 15, 2, 2, 5 Country C: 4, 6, 20, 17, 15, 30, 18, 18, 25, 2, 29, 17, 16, 35, 19, 1, 30, 25, 16, 15

A) Country A

B) Country B

C) Country C

D) Countries B and C were equal

Answer: C


9) The most common single number in a group of scores is the:

A) mode

B) mean

C) median

D) average

Answer: A

10) What is the mode of the following scores: 3, 4, 6, 7, 10, 10, 30, 10, 30, 4, 3, 8 ?

A) 3

B) 4

C) 8.5

D) 10

Answer: D

11) Based on the following scores 1, 2, 3, 4, 5, 6, 8, 8, 8, 9, 10, a score of 8 is the:

A) mean

B) median

C) mode


Answer: C

12) What is the median of the following group of scores: 1, 2, 2, 3, 4, 4, 4, 6, 8, 10?

A) 3

B) 5.5

C) 4

D) 3.5

Answer: C

13) The middle value in a set of scores lined up from lowest to highest is the:

A) mean

B) mode

C) average

D) median

Answer: D


14) What is the median of the following scores: 4, 4, 6, 7, 8, 8, 9, 10, 11, 2, 1, 4?

A) 4

B) 5.5

C) 6.5

D) 8.5

Answer: C

15) A Canadian political scientist discovers that the number of members of their provincial parliament that a group of voters can name is as follows: 3, 3, 3, 4, 4, 5, 6, 7, 8, 9, 10, 35. Upon examination of these scores, the researcher would probably decide to use which measure of the typical value?

A) Mean

B) Median

C) Mode

D) Standard deviation

Answer: B

16) Which statement is true for the scores 1, 2, 3, 4, 5, 5, 7, 8, 9, 10, 12, 12, 13?

A) The mode is greater than the median

B) The median is greater than the mean

C) The median is greater than the mode

D) The mode is greater than the mean

Answer: C

17) When a distribution is skewed to the right:

A) the median is greater than the mean

B) the mean and the median are the same

C) the mean is greater than the median

D) the mean and the median are equal

Answer: C

18) The median is greater than the mean in a distribution that is:

A) symmetrical

B) skewed to the right

C) normal

D) skewed to the left

Answer: D


19) The capital Greek letter “sigma” is the symbol for:

A) “average of”

B) “sum of”

C) “variance of”

D) “median of”

Answer: B

20) In a perfectly symmetrical unimodal distribution:

A) there are two values with the highest frequency of scores

B) the mode is slightly less than the mean

C) the mean is larger than the median

D) the mode is the same as the mean

Answer: D

21) The mode can be a poor representative value because:

A) it can be difficult to calculate without a statistical software package

B) it does not reflect many aspects of the distribution

C) it is generally larger than the mean

D) all of the above

Answer: B

22) The ________ is the usual way of describing the representative value for a nominal variable such as religious affiliation.

A) mean

B) outlier

C) median

D) mode

Answer: D

23) In a distribution with an even number of scores, the median will be the:

A) most common value

B) average of the two middle scores

C) the median divided by the mean

D) the sum of score divided by N – 1

Answer: B


24) Unless there are __________ , behavioral and social scientists generally use the mean as the measure of the representative value of a group of scores.

A) outliers

B) histograms

C) Z scores

D) two modes

Answer: A

25) While the mean provides a representative value of a group of scores, it does not tell about the __________.

A) variability of the scores

B) average of the scores

C) spread of the scores around the mean

D) both A and C

Answer: D

26) Place the five steps for computing variance into the correct order: 1. Divide the sum of squared deviations by the number of scores. 2. Subtract the mean from each score. 3. Add up the squared deviation scores. 4. Compute the mean of the sample. 5. Square each of the deviation scores.

A) 2, 3, 1, 4, 5

B) 5, 1, 2, 4, 3

C) 4, 5, 2, 1, 3

D) 4, 2, 5, 3, 1

Answer: D

27) In order to compute the range of a group of scores, one must:

A) subtract the lowest score from the highest score

B) multiply the lowest score by the average

C) multiply the highest score by the average

D) subtract the lowest score from the highest and divide by N

Answer: A


28) The variance of a group of scores is the same as the:

A) average of the squared deviations from the mean

B) sum of the squared deviations about the mean

C) average of the absolute deviations from the mean

D) sum of the absolute deviations from the median

Answer: A

29) In a class of students in which everyone is exactly 24 years old, the variance would be:

A) approximately 1

B) exactly 0

C) between 0 and 1

D) impossible to determine without more information

Answer: B

30) The variance of a group of scores is 9. What is the standard deviation?

A) 1

B) 3

C) 4.5

D) 81

Answer: B

31) The most widely used way of describing the spread of a group of scores is the:

A) range

B) variance

C) square root transformation


Answer: D

32) Roughly speaking, the standard deviation is the average amount that scores differ from the:

A) histogram

B) median

C) mean

D) range

Answer: C


33) The standard deviation is defined as the:

A) positive square root of the variance

B) positive square root of the range

C) negative square root of the variance

D) positive square root of the mean or median

Answer: A

34) Measures of variability, such as the variance and standard deviation, are heavily influenced by the presence of one or more:

A) average scores

B) computational formulas

C) variables

D) extreme scores or outliers

Answer: D

35) The standard deviation of a group of scores is 4. What is the variance?

A) 2

B) 4

C) 8

D) 16

Answer: D

36) A researcher surveys job satisfaction among laborers and white-collar workers. (Job satisfaction is rated on a scale from 1 = low satisfaction to 10 = high satisfaction.) Results show that laborers have a mean job satisfaction score of 3 and a variance of 1; white-collar workers have a mean job satisfaction rating of 7 and a variance of 10. Which statement best describes what these numbers mean?

A) White-collar workers are less satisfied than laborers.

B) White-collar workers and laborers are about equally satisfied.

C) Laborers generally are less satisfied than white-collar workers, but laborers are just as likely to be highly satisfied as white-collar workers are to be highly dissatisfied.

D) Laborers are less satisfied than white-collar workers and most laborers are about equally dissatisfied while there is more variation in the satisfaction of white-collar workers.

Answer: D


37) What is the variance of these three scores: 1, 4, 7?

A) 3

B) 4

C) 6

D) 9

Answer: C

38) What is the variance of these four scores: 0, 1, 1, 2?

A) .25

B) .5

C) .86

D) 1

Answer: B

39) What is the standard deviation of these four scores: 2, 4, 3, 7?

A) 1.87

B) 2.35

C) 3.50

D) 4.05

Answer: A

40) In a distribution of Z scores, the mean is always:

A) 10

B) 1

C) 0

D) 50

Answer: C

41) A __________ describes a particular score in terms of where it fits into the overall group of scores.

A) standard deviation

B) computational formula

C) Z score

D) Q score

Answer: C


42) All of the following are true statements about a Z score EXCEPT:

A) it is the number of standard deviations the actual score is above or below the mean

B) it is negative if the actual score falls below the mean

C) it is negative if the actual score falls above the mean

D) it is zero if the actual score falls at the mean

Answer: C

43) Donald’s score on the statistics test was +1.25. This means that he scored:

A) slightly below the average

B) just at the average

C) a little less than one standard deviation below the mean

D) more than one standard deviation above the mean

Answer: D

44) As compared to a Z score, a raw score is:

A) a transformed score

B) an ordinary score

C) a scaled score

D) a standardized score

Answer: B

45) Which of the following is NOT an advantage of Z scores?

A) You can compare scores from scales with different amounts of variation.

B) You can easily tell if a score is above or below the mean.

C) You can easily tell how far above or below the mean a score is.

D) You can easily tell the shape of the scores’ distribution.

Answer: D


46) For the questions below: A statistics student (Lee) wants to compare his final exam score to his friend Zoey’s final exam score from last year. However, the two exams were scored on different scales. Lee asks Zoey for the mean and standard deviation of her class on the exam as well as her final exam score. Compute the Z scores for Lee and Zoey. Lee: Final exam score = 85; Class: M = 70; SD = 10 Zoey: Final exam score = 45; Class: M = 35; SD = 5

A) Lee, Z = 1.50; Zoey, Z = 2.00

B) Lee, Z = −1.07; Zoey, Z = −1.14

C) Lee, Z = 1.07; Zoey, Z = −1.14

D) Lee, Z = 1.07; Zoey, Z = 1.50

Answer: A

47) In relation to the other people in their classes, who had the better exam score?

A) Lee

B) Zoey

C) They were equal

D) It is not possible to say without more information

Answer: B

48) A Z score of 2.0 came from a distribution with a mean of 80 and a standard deviation of 10. What is the raw score?

A) 82

B) 90

C) 100

D) 170

Answer: C

49) A person’s raw score is 7, the mean is 13, and the standard deviation is 3. What is the person’s Z score?

A) −2

B) −1

C) 1

D) 2

Answer: A


50) A raw score is equal to the:

A) Z score multiplied by the standard deviation, plus the mean

B) Z score multiplied by the variance, plus the mean

C) standard deviation multiplied by the mean, plus the variance

D) raw score minus the mean, divided by the variance

Answer: A

51) For a particular group of scores, M = 20 and SD = 5. What is the Z score for a raw score of 10?

A) 2

B) 0

C) −2

D) −1

Answer: C

52) For a particular group of scores, M = 15 and SD = 3. Provide the raw score for a Z score of 7:

A) 15

B) 24

C) 36

D) 48

Answer: C

53) Who was the behavioral psychologist opposed to the use of statistics in psychology?

A) Cohen

B) McCracken

C) Cronbach

D) Skinner

Answer: D

54) A researcher studying the sociological implications of cultural diversity conducts lengthy interviews with members of various cultural communities. What kind of method is this sociologist probably using?

A) Behavioral techniques

B) Quantitative techniques

C) Qualitative techniques

D) Positivistic techniques

Answer: C


55) Although __________ and __________ are often provided in research articles (in the text or tables), _________ are rarely reported.

A) variance, range, Z scores

B) Z scores, T scores, means

C) means, standard deviations, Z scores

D) outliers, Z scores, means

Answer: C

56) Match the term on the left with its correct definition on the right

A) definitional formula 1) ordinary score (or any other number in a distribution before it has been made into a Z score)

B) raw score 2) approximately the average amount that scores in a distribution vary from the mean

C) Z score 3) equation for a statistical procedure directly showing the meaning of the procedure

D) standard deviation 4) number of standard deviations a score is above or below the mean of its distribution

Answer: A-3; B-1; C-4; D-2

57) Whose name is associated with behaviorism and opposition to the field of statistics on the basis that important information may be lost by averaging the results of a number of cases?

A) James

B) Freud

C) Wolpe

D) Skinner

Answer: D

58) Qualitative research techniques are likely to involve each of the following EXCEPT:

A) lengthy interviews

B) focus groups

C) quantitative methods (e.g., statistics)

D) observations of individuals (e.g., in natural settings)

Answer: C


59) A research article states that “At the time of the study, the mean age of first-year college students at Wayne University was 17.6 (3.57). The number in parentheses likely represents:

A) the Z score

B) the standard deviation

C) the mode

D) an outlier

Answer: B

60) The ordinary arithmetic average is called the __________.

Answer: mean

61) The mean of the scores 2, 2, 2, 6 is __________.

Answer: 3

62) A group of scores is 6, 7, 7, 8, 10, 11. What is N?

Answer: 6

63) The __________ is the value with the most scores.

Answer: mode

64) A group of scores is 2, 2, 4, 8, 9, 2, 10, 15, 30, 30. What is the mode?

Answer: 2

65) A group of scores is 6, 18, 4, 21, 22. __________ is the median.

Answer: 18

66) In statistics, the best measure of the representative value of a group of scores is usually the mode. (True or False)

Answer: FALSE

67) In a perfectly symmetrical unimodal distribution, the mode is the same as the mean. (True or False)

Answer: TRUE

68) A group of scores is 2, 2, 4, 8, 9, 25. What is the median?

Answer: 6

69) A group of scores is 2, 81, 82, 82, 84, 86, 90. The number __________ is an outlier.

Answer: 2


70) The variance of a group of scores is the average of the __________.

Answer: squared deviations from the mean, squared deviations

71) The variance of the scores 1, 7, 13 is __________.

Answer: 24

72) A deviation score is the difference between the score and the __________.

Answer: mean

73) The __________ is approximately the average that a score differs from the mean.

Answer: standard deviation

74) The standard deviation is the __________ of the variance.

Answer: square root, positive square root

75) A(n) __________ is the number of standard deviations a score is above or below the mean.

Answer: Z score

76) A Z score is −3 and the sample’s M = 30 and SD = 6. The raw score is __________.

Answer: 12

77) A raw score is 28, M = 20, and SD = 2. The Z score is __________.

Answer: 4

78) Alex’s Z score on his abnormal psychology exam was −.05, indicating that he scored well above the mean on the exam. (True or False).

Answer: FALSE

79) The formula for changing a Z score to a raw score is __________.

Answer: X = (Z)(SD) + M

80) Behaviorists such as B. F. Skinner sometimes object to the use of statistics in research because averages can distort the pattern of information revealed from observing the behavior of __________.

Answer: each individual case

81) List the three most widely used ways to describe a typical or representative value and explain what each tells a researcher.


82) Make up three sets of scores for eight people who took a verbal ability test (test ranges from 20 to 60 points). For one set of scores, the mean should be greater than the median. For the second set of scores, the mean and median should be equivalent. For the third set of scores, the mode should be greater than both the mean and median.

83) Make up an example in which the median would be the preferred measure of the representative value of a group of scores.

84) The tiger at the local zoo lived to the age of 28 while the elephant lived to the age of 65. Explain to someone unfamiliar with statistical techniques which animal lived longer relative to the expected lifespan of its species? Use the information provided below to help answer the question. Average lifespan of a tiger = 22 (SD = 3) Average lifespan of an elephant = 70 (SD = 7)

85) Based on an analysis of personnel records, an organizational specialist reports that for her company: “During the last year, the mean number of sick days taken by shop employees was 7.3 with a standard deviation of 6.1.” Explain what this result means to a person who has never had a course in statistics.

86) During the winter, a survey is conducted at a particular college regarding the number of hours spent outside on weekends. The survey reports that for students from cold-weather climates, M = 8, SD = 1.5. For students from warm-weather climates, M = 5, SD = 4.2. Explain what these numbers mean and the conclusions one should draw from this study.

87) Here are the average snowfalls (in inches) for a particular northern U.S. city on consecutive February days during the winter of 2007: 0, 0, 2, 2, 4, 5, 0, 0, 6, 15. Describe the representative (typical) snowfall and the amount of variation in this city. Provide three ways of describing the representative snowfall and two ways of describing its variation, explaining differences in how you calculated each value.

88) How might researchers combine quantitative and qualitative methodologies to improve psychological research?

89) Five high school English teachers were given a grammar test. Their scores were as follows: 17, 19, 14, 20, 20.

Figure the mean, mode, variance, and standard deviation for this sample. Explain what you have done and what the results mean to a person who has never had a course in statistics.

Answer: Mean = 90/5 = 18 Mode = 20 Variance = 1 + 1 + 16 + 4 + 4 = 26/5 = 5.2 Standard Deviation = square root of 5.2 = 2.28


90) A teacher rated the reading ability level of six fourth-grade children participating in a special math program. The ratings were as follows: 3, 3, 2, 8, 4, 4.

Figure the mean, variance, and standard deviation for this group of scores. Explain what you have done and what the results mean to a person who has never had a course in statistics.

Answer: Mean = 24/6 = 4 Mode = bimodal(3 and 4) Variance = 1 + 1 + 4 + 16 + 0 + 0 = 22/6 = 3.67 Standard Deviation = square root of 3.67 = 1.92

91) A museum curator was interested in people’s responses to art. She therefore had seven people indicate their liking for a particular piece of Egyptian sculpture. Their ratings were as follows: 2, 4, 4, 5, 6, 7, 7.

Figure the mean, median, mode, variance, and standard deviation for this group of scores. Explain what you have done and what the results mean to a person who has never had a course in statistics.

Answer: Mean = 35/7 = 5 Median = 5 Mode = bimodal(4 and 7) Variance = 9 + 1 + 1 + 0 + 1 + 4 + 4 = 20/7 = 2.86 Standard Deviation = square root of 3.67 = 1.69

92) After attending an anxiety-reduction therapy session, a wife’s anxiety score is 75, while her husband’s is 80. Overall, women’s average anxiety score after the sessions is 70 (SD = 10) and men’s average anxiety score after the sessions is 85 (SD = 5).

Relative to others of their own gender, who has the lower anxiety score after the session? Explain your answer to someone who has never had a course in statistics.

Answer: Wife’s Z = .5; Husband’s Z = −1. Thus, wife is more anxious relative to her gender. (Note: Lower score = positive outcome/reduced anxiety. Thus, negative Z scores indicate lower anxiety.)


93) A business researcher has to decide which of three employees should be placed in a particular job that requires a high level of perceptual–motor coordination. All three employees have taken tests of perceptual–motor coordination, but each took a different test. Employee A scored 15 on a test with a mean of 10 and a standard deviation of 2. Employee B scored 350 on a test with a mean of 300 and a standard deviation of 40. Employee C scored 108 on a test with a mean of 100 and a standard deviation of 16. On all three tests, higher scores mean greater coordination.

Which employee has the best perceptual–motor coordination? Explain your answer to someone who has never had a course in statistics.

Answer: Employee A’s Z = 2.5; Employee B’s Z = 1.25; Employee C’s Z = .5. Thus, Employee A has the best perceptual–motor coordination and should be given the job.

94) A clinical psychologist administered a standard test of symptoms of three different behavioral disorders to a new patient at a mental health clinic. On the scale that measures Disorder F (in the general public, M = 60, SD = 8), the person’s score is 62. On the scale that measures Disorder H (in the general public, M = 32, SD = .5), the person’s score is 34. And on the scale that measures Disorder K (in the general public, M = 83, SD = 12), the person’s score is 89.

For the symptoms of which disorder or disorders did this person score substantially higher than the general public? Explain your answer to someone who has never had a course in statistics.

Answer: Disorder F, Z = .25; Disorder H, Z = 4; Disorder K, Z = .5. Thus, only on Disorder H are the person’s symptoms substantially higher than for the general public.

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