Using techniques from

Section 7.2, we can find a confidence interval for md. Consider a random sample

of n matched data pairs A, B. Let be a random variable representing

the difference between the values in a matched data pair. Compute the

sample mean of the differences and the sample standard deviation sd. If d has

a normal distribution or is mound-shaped, or if , then a confidence

interval for md is

a) Using the data of Problem 9, find a 95% confidence interval for the mean

difference between percentage increase in company revenue and percentage

increase in CEO salary.

(b) Use the confidence interval method of hypothesis testing outlined in Problem 25

of Section 8.2 to test the hypothesis that population mean percentage increase

in company revenue is different from that of CEO salary. Use a 5% level of

significance.