Question

Using techniques from an earlier section, we can find a confidence interval for μd. Consider a random sample of n matched data pairs A, B. Let d = B − A be a random variable representing the difference between the values in a matched data pair. Compute the sample mean d of the differences and the sample standard deviation sd. If d has a normal distribution or is mound-shaped, or if n ≥ 30, then a confidence interval for μd is as follows. d − E < μd < d + E where E = tc sd n c = confidence level (0 < c < 1) tc = critical value for confidence level c and d.f. = n − 1 B: Percent increase for company 16 10 10 18 6 4 21 37 A: Percent increase for CEO 18 20 15 14 −4 19 15 30

(a) Using the data above, find a 95% confidence interval for the mean difference between percentage increase in company revenue and percentage increase in CEO salary. (Round your answers to two decimal places.) lower limit upper limit

Answer 1