Question 1

The distribution of weights of female college cross-country runners is approximately normal with mean 122 pounds and standard deviation 8 pounds. Which of the following is closest to the percent of the runners who weigh between 114 pounds and 138 pounds?

Accepted Answer

82%

Answer

95%

Answer

18%

Answer

32%

Question 2

The pulse rate for each person in a sample of 20 men and 20 women was recorded. The boxplots below summarize the pulse rates for the men and the women in the sample.

Accepted Answer

At least half of the women had higher pulse rates than three-fourths of the men.

Answer

The person with the lowest pulse rate is a woman.

Answer

There are more people between the first and third quartiles for women than there are between the first and third quartiles for men.

Answer

More than half of the men had lower pulse rates than three-fourths of the women.

Question 3

Data will be collected on the following variables. Which variable can be considered discrete?

Accepted Answer

The number of books a person finished reading last month

Answer

The length of a person’s arm span

Answer

The time it takes for a person to solve a puzzle

Answer

The weight of a person

Question 4

The following relative frequency table shows the political party affiliation for a sample of 500 people in a certain town. Which of the following statements is supported by the table?

Accepted Answer

The number of people affiliated with the Independents is 100.

Answer

Less than half of the people are affiliated with the Democrats or the Republicans.

Answer

The number of people affiliated with the Republicans is 30.

Answer

At least 80 people are affiliated with the Green Party or the Libertarians.

Question 5

A researcher studying a specific type of tree creates a least-squares regression line for relating the height and the diameter, both in meters, of a fully grown tree. The results are shown in the following computer output. Which of the following values represents the predicted change in the height of the tree for each one-meter increase in the diameter of the tree?

Accepted Answer

30

Answer

2.50

Answer

5

Answer

4.00

Question 6

The following segmented bar chart shows the number of flights that were either on time or delayed at three different airports on one day. Which of the following statements is supported by the bar chart?

Accepted Answer

The number of on-time flights at Airport S is half the number of on-time flights at Airport T.

Answer

Airport T has the greatest percentage of on-time flights compared to the other two airports.

Answer

The number of on-time flights at Airport R is less than the number of on-time flights at Airport S.

Answer

Airport R has the least percentage of on-time flights compared to the other two airports.

Question 7

A scatterplot of student height, in inches, versus corresponding arm span length, in inches, is shown below. One of the points in the graph is labeled A. If the point labeled A is removed, which of the following statements would be true?

Accepted Answer

The slope of the least squares regression line increases and the correlation coefficient increases.

Answer

The slope of the least squares regression line is unchanged and the correlation coefficient decreases.

Answer

The slope of the least squares regression line is unchanged and the correlation coefficient increases.

Answer

The slope of the least squares regression line increases and the correlation coefficient decreases.

Question 8

Which of the following distinguishes an observational study from a randomized experiment?

Accepted Answer

In an observational study, treatments are not randomly assigned, whereas in a randomized experiment treatments are randomly assigned.

Answer

In an observational study, volunteers are always used, whereas in a randomized experiment a random sample is always taken from the population.

Answer

In an observational study, a random sample is always taken from the population, whereas in a randomized experiment volunteers are always used.

Answer

An observational study can be double-blind, whereas a randomized experiment can only be single-blind because the experimenter determines who is randomly assigned to each treatment.

Question 9

In the design of a survey, which of the following best explains how to minimize response bias?

Accepted Answer

Carefully word and field-test survey questions.

Answer

Increase the number of questions in the survey.

Answer

Decrease the sample size.

Answer

Randomly select the sample.

Question 10

A program that was intended to cure a person’s fear of spiders was offered at a local zoo. Volunteers with a fear of spiders participated in the program, which included holding a spider for 15 minutes. One month after they completed the program, the participants were contacted and surveyed about the program. Over 90 percent of the participants claimed they were cured of their fear of spiders. Based on the description of the program, which of the following statements is true?

Accepted Answer

Because the participants were self-selected, a person’s desire to be cured could be a confounding variable.

Answer

Because over 90% of the participants claimed to be cured, the results can be generalized to the population of all people who have a fear of spiders.

Answer

Because participants held a spider for 15 minutes, the study is an experiment and the results can be generalized to the population of all people who have a fear of spiders.

Answer

Because over 90% of the participants claimed to be cured, the results prove that holding a spider will cure a person’s fear of spiders.

Question 11

A student is applying to two different agencies for scholarships. Based on the student’s academic record, the probability that the student will be awarded a scholarship from Agency A is 0.55 and the probability that the student will be awarded a scholarship from Agency B is 0.40. Furthermore, if the student is awarded a scholarship from Agency A, the probability that the student will be awarded a scholarship from Agency B is 0.60. What is the probability that the student will be awarded at least one of the two scholarships?

Accepted Answer

0.62

Answer

0.71

Answer

0.95

Answer

0.73

Question 12

Amy has 12 brown golf tees, 8 white golf tees, 10 red golf tees, 6 blue golf tees, and 12 green golf tees in her golf bag. If she selects one of the tees from the bag at random, what is the probability that she selects a tee that is not brown or blue?

Accepted Answer

$\frac{5}{8}$

Answer

$\frac{7}{8}$

Answer

$\frac{3}{8}$

Answer

$\frac{21}{32}$

Question 13

For the lunch special at a high school cafeteria, students can get either salad or french fries as a side order. The following table shows the number of each side order for the lunch specials purchased on one day, classified by the grade of the student. From those who purchased the lunch special that day, one student will be selected at random. What is the probability that the student selected will be in grade 10 given that the student ordered french fries as the side order?

Accepted Answer

$\frac{71}{248}$

Answer

$\frac{71}{105}$

Answer

$\frac{248}{248}$

Answer

$\frac{71}{368}$

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