Chapters 2–7  AP Practice Quiz

Name ________________________________________________________ Date ___________________

1. The standard deviation of this distribution is closest to which value?

0.25

0.5

1

3.5

4

2. A coefficient of determination, , is found to be 0.81. Which of these statements is true?

81% of the variation between the variables is accounted for in the linear relationship.

81% of the data points lie on a line.

The correlation coefficient is 0.9.

19% of the variation between the variables is accounted for in the linear relationship.

All of these are true.

3. In order to assess the membership’s attitudes about a new Supreme Court decision, a local bar association selects a simple random sample of 100 lawyers from its membership list. Surveys are delivered to the selected lawyers. Only 63 of the lawyers return their surveys. Which of these is of great concern in this situation?

Nothing is known about the parameters of population interest.

Nothing is stated regarding the methodology of the simple random sample.

There may be a problem with the sampling frame.

There may be a problem with nonresponse bias.

None of these statements is of concern.

4. A personnel director at a large company studied the eating habits of employees by watching the movement of a selected group of employees at lunchtime. The purpose of the

study was to determine the proportions of employees who buy lunch in the cafeteria, bring their own lunches, and go out to lunch.

If the director includes only the employees in one department in her study, she has a

simple random sample

quota sample

convenience sample

multistage cluster sample

census

5. Two simple random samples of 50 students from two different universities are taken to determine the proportion of students who approve of the food service at their respective schools. The first university has an enrollment of 5,000 students, while the second university has an enrollment of 35,000. Which of these is the best statement regarding possible bias in the estimates?

There is more bias with the larger university.

There is more bias with the smaller university.

No bias is expected because the sample sizes are equal.

No bias is expected because both populations are at least 10 times the sample size.

No bias is expected because these are random samples.

6. College entrance examination scores have an approximately normal distribution with mean 500 and standard deviation 100.

a. If you select one score at random, what is the probability that it is 510 or greater?

b. If you select four scores at random, what is the probability that their average is 510 or greater?

c. If you select 25 scores at random, what is the probability that their average is 510 or greater?

d. Explain how to use simulation to find the probability that each of four randomly selected scores is 510 or greater.

Statistics in Action Instructor’s Resource Book Chapters 2–7 AP Practice Quiz 1

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