Warm-upAn Exercise in Sampling: Rolling Down the River

1. What will the treatment be?2. What will the response variable be?3. How will the response variable be measured?4. What will the experimental unit be?5. Specify the experimental conditions to be used byconsidering factors that might have ….what, if anything,should be done to control this variation.6. Skip this one…

4.3 E #25 – 26 a and b25) a. There is radomization of the 10 plants there are splitinto the 2 groups. There is replication. Five plants are gettingeach of the treatments. There is a control group because 5plants are replanted in their natural environment.b. All ten plants need to be dug up so that confoundingvariables such as sun/shade are not confounded by dug upand not dug up.26) a. The factors are powder and temperature. The levels arethe 2 types of powder and the 3 types of temperature. Thereare 6 types of treatments.b. The metallurgist should use randomization in and test only onetype of treatment at a time since there is only one oven. Thereshould also be an equal number of powders in randomly selectedareas of the oven.

4.3 # 26 c. and 27

c. This experiment could be blind if an assistant was theone to randomly selected the powder for each of the 3temperatures. The metallurgist could record the results. 27. The units in this experiment are the dormitories.There are 20 dormitories. This is an experimental study.

Student of the day!Block 4

Student of the day!Block 5

Student of the day!Block 6

Instructions for An Exercise in SamplingRolling Down the River

1) Answer all questions on a piece of paper in complete sentences.2) BEFORE answering questions, for Sampling Methods B,C, D draw the 10 x 10 plot and explain how you used yourcalculator to do the specified sampling. Also show theresults of the plots chosen using your method.3) Also be sure to include the table with resultsbefore the observation questions.4) For Observation #4 we will be writing the results on theboard to the right of the classroom. 5) For Part II redraw the 10x10 plots describe yourmethods briefly if you used the same methods.

A.P. Statistics Selected Ch. 3 Test Answers5. a. for the slope A, B, C was okay because the residual plot had too much variation. But the answers was really B. c. Is the correlation coefficient a goodmeasure of association to use with the diameter versus age data?Briefly explain your answer. In part b. most of you calculated it to be0.9 and said the association was strong BUT there was a patter in theresidual so the correlation coefficient is not a good measure becausethe relationship may not be linear or there may be a lurking variable.6. For the function 0.735 year – 59.5; it was important to describe∙slope as for every year younger the model of the car was the pricewent up $735. Lost 1 of 2 pts if you were not specific enough.

A.P. Statistics 7.

a.Solve for R2

b. 67% of the variation in calories can be attributed to the amount of fat.

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Statistics Common Mistakes on Test

5. a. A – C was fine. It was really B. b. If the standard deviation of the fuel consumption is approximately976.7 gal/h and the standard deviation of the speed is 54.8 mi/h, findthe correlation between fuel consumption and speed.c. The residual plot had a pattern so the correlation coefficient,although it is considered strong, it is not a good indicator of therelationship between speed and fuel consumption. The U-shape of theresidual means that the relationship is not linear OR that there is alurking variable.

fuel consumption = –5465.5 + 15.50 · speed

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Statistics Common Mistakes on Test

8.

b.

c. The R2 is the coefficient of determination which describes the proportion of variation in the diameter that is determined by age.

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Be Ready for 4.1 to 4.3 Vocabulary Quiz Next Class

population, sample, sample size, sampling frame,voluntary response bias, convenience sampling,judgment samples, size bias, biased samplingmethods, unrepresentative sample, nonresponse bias,questionnaire bias simple random sample, clustersample, probability sample, two-stage sample andmultistage sample, strata, stratified random sample,lurking variable, confounding variable, experimentalstudy, observational study, control group, blind study,double-blind study, experimental units, randomization oftreatment to subjects, replication, factors, levels,

randomizedblock design, replication

A.P. Statistics and Statistics H.W.

• For those teams that did not win the game, read and define 4.3 and 4.4 terms.

• EVERYONE needs to complete up to #3 on Part 1 of the Rolling Down the River Activity

• EVERYONE should prepare for the 4.1 to 4.3 Vocabulary Quiz