1. Does listening to music while working out have an impact on the length of the workout? A sample of college students was randomly assigned to one of two groups. One group worked out on a treadmill while listening to rock music playing the background; the other group worked out on a treadmill with no music playing in the background. It was found that those who worked out while rock music was playing spent more minutes on the treadmill, on average, than those who were working out with no music playing. The explanatory variable in this experiment is

a. the length of the workout.

b. whether or not music was playing.

c. the college students.

d. the researchers.

2. Heights are measured, in inches, for a sample of undergraduate students, and the five-number summary for this data set is given in the table below.From this five-number summary, what can we conclude?

Minimum	Q1	Median	Q3	Maximum
59	64	67	69	74

a. 50% of the heights are between 59 inches and 74 inches.

b. 75% of the heights are below 64 inches.

c. 25% of the heights are above 69 inches.

d. 25% of the heights are between 67 and 74 inches.

e. 50% of the heights are between 59 and 69 inches.

3. A researcher is designing an experiment. Ultimately, she is hoping to reject her null hypothesis (i.e., show that the results of her experiment are statistically significant). What type ofp-value would she want to obtain?

a. A large p-value.

b. A small p-value.

c. The size of a p-value has no impact on statistical significance.

4. If you flip a fair coin 9 times, and all 9 tosses came up "heads," what is the probability that the next coin toss will result in "heads"?

a. Exactly 0.5.

b. Less than 0.5.

c. Greater than 0.5.

d. Impossible to determine because coin tosses are random.

5. Consider a large number of countries around the world. There is a positive correlation between the number of Nintendo games per person (x) and the average life expectancy (y). Does this mean that we can increase the life expectancy in a country by shipping more Nintendo games to that country?

a. Yes. As long as a correlation is positive, we can conclude that one variable causes the other.

b. No. We can only conclude that one variable causes another if the variables are negatively correlated.

c. Yes, but it will depend on how strong the correlation is; as long as the correlation is larger than 0.70, we can conclude that one variable causes the other.

d. No. An association between two variables does not mean that one variable causes the other.

6. A survey of homes in Whitehall, Ohio recorded the market value of the home (y) in dollars and the size of the home (x) in square feet. The resulting regression equation was as follows:

Predicted market value = -34778 + 94.2(square feet)

From this equation, we know the correlation between market value and size of the home will be

a. negative.

b. positive.

c. zero.

d. very strong.

e. It's impossible to answer this question without more information.

7. Assume that observing a boy or girl in a new birth is equally likely. If we observe fourbirths in a hospital, which of the following outcomes is most likely to happen?

a. Girl, Girl, Girl, Girl

b. Boy, Girl, Boy, Girl

c. Boy, Boy, Girl, Girl

d. Boy, Boy, Boy, Boy

e. All of the above are equally likely

8. You determine that the standard deviation for a sample of test scores is 0. This tells you that

a. all the test scores must be 0.

b. all the test scores must be the same value.

c. there is no straight-line association.

d. the mean test score must also be 0.

e. you made a mistake because the standard deviation can never be 0.

9. A 95% confidence interval for the proportion of young adults who skip breakfast is .20 to .27. Which one of the following is a correct interpretation of this 95% confidence interval?

a. We are 95% confident that the sample proportion of young adults who skip breakfast is between .20 and .27.

b. We are 95% confident that the proportion of young adults in the population who skip breakfast is between .20 and .27.

c. The proportion of young adults who skip breakfast 95% of the time is between .20 and .27.

d. We are 95% confident no mistakes were made when the interval from .20 to .27 was computed.

10. Data was collected about the number of text messages a sample of college students received in the last day.In this particular sample, most students received few text messages, but a small number of students received a very large number of text messages.Two measures of center were computed for this sample:15.6 and 20.2.One of these measures is the mean and one is the median.Which measure must be the median?

a. The median is 20.2 because the distribution of number of text messages would be skewed to the left.

b. The median is 20.2 because the distribution of number of text messages would be skewed to the right.

c. The median is 15.6 because the distribution of number of text messages would be skewed to the left.

d. The median is 15.6 because the distribution of number of text messages would be skewed to the right.