11.45 In Example 11.9 (p. 430), we compared the number of hours of computer time with the number of hours watching TV by finding a 90% confidence interval.

a. Find a 95% confidence interval for this situation, and write a sentence interpreting it.

b. Draw a picture similar to Figure 11.9 on page 433 illustrating the confidence interval you found in part (a).

c. On the basis of the 95% confidence interval that you found in part

(a) and/or the picture you drew in part (b), can you conclude that for the population represented by this sample, students really do spend more time on computer usage than on watching television, on average?

Explain.

d. Refer to the three ways that paired data can occur, listed following the definition on page 415. Which of the three best describes the situation in this exercise?

Explain.

General Section Exercises