AP Stats MCQ Exam

In order to plan its next advertising campaign, the Trendy Motor Vehicle Company is investigating whether the type of vehicle and the color of vehicle are related. Each person in a random sample of size 275 selected from the company’s mailing list was classified according to the type (car or truck) and the color of vehicle he or she drove. The data are shown in the table below.

A table is shown with columns representing vehicle color and rows representing vehicle type. The labels for the columns are red, black, white, tan, and green. The first row is car, 35, 23, 41, 21, and 12. The second row is truck, 27, 55, 39, 12, and 10.

Which of the following procedures would be most appropriate to use for investigating whether there is a relationship between vehicle type and color?

Responses

A

A two-sample t-test

B

A two-sample z-test

C

A matched pairs t-test

D

A chi-square goodness-of-fit test

E

A chi-square test of independence

A national health study reported that the proportion of students with elevated blood pressure is 0.15. The principal of a local high school believes that the proportion of students in the school with elevated blood pressure is greater than 0.15. If a large random sample is used, which of the following is the most appropriate test to investigate the principal’s belief?

Responses

A

A z-test for a proportion

B

A z-test for a difference between two proportions

C

A chi-square test for homogeneity of proportions

D

A t-test for a mean

E

A matched-pairs t-test

A sports equipment researcher investigated how different types of wood used to make baseball bats might affect batting. The researcher selected a sample of 80 batters from summer baseball leagues and randomly assigned the batters to one of two groups: the ash bat group or the maple bat group. The mean number of hits for each group was recorded at the end of the season, and the difference in the sample means was calculated.

Which of the following is the appropriate inference procedure for analyzing the results of the investigation?

Responses

A

A one-sample

-interval for a population mean

B

A one-sample

-interval for a sample mean

C

A matched pairs

-interval for a mean difference

D

A two-sample

-interval for a difference between sample means

E

A two-sample

-interval for a difference between population means

A fitness center offers a one-month program designed to reduce body fat through exercise. The table shows the body fat percentage before and after completing the program for 10 randomly selected participants.

The figure presents a 3-row table. The heading for row 1 is “Participant,” the heading for row 2 is “Before, in percent,” and the heading for row 3 is “After, in percent.” There are 10 columns of data. The data in the table are as follows. Participant A. Before, 10.8%. After, 10.7%. Participant B. Before, 21.5%. After 20.4%. Participant C. Before, 18.9%. After, 19.1%. Participant D. Before, 17.0%. After, 16.1%. Participant E. Before, 20.8%. After, 20.6%. Participant F. Before, 24.6%. After, 22.3%. Participant G. Before, 15.4%. After, 15.5%. Participant H. Before, 18.2%. After, 18.1%. Participant I. Before, 19.9%. After, 18.5%. Participant J. Before, 21.2%. After, 20.0%.

The director of the program wants to investigate whether knowing the body fat percentage before beginning the program can help to predict body fat percentage for someone who completes the program.

Which of the following procedures is the most appropriate for such an investigation?

Responses

A

A matched-pairs t-test for a mean difference

B

A two-sample t-test for a difference between means

C

A two-sample z-test for a difference between proportions

D

A chi-square test of association

E

A linear regression t-test for slope

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Random Variable Graded Assignment

Random Variable Graded Assignment

The following table shows the probability distribution for the number of books a student typically buys at the annual book fair held at an elementary school.

Number of Books 0 1 2 3 4 5 6 7

Probability 0.35 0.20 0.15 0.10 0.07 0.08 0.04 0.01

Let the random variable

represent the number of books a student buys at the next book fair. What is the expected value of

?

Responses

A

0

B

1.00

C

1.79

D

3.50

E

28