Question

In this problem, assume that the distribution of differences is approximately normal. Note: For degrees of freedom d.f. not in the Student's t table, use the closest d.f. that is smaller. In some situations, this choice of d.f. may increase the P-value by a small amount and therefore produce a slightly more "conservative" answer.

Are America's top chief executive officers (CEOs) really worth all that money? One way to answer this question is to look at row B, the annual company percentage increase in revenue, versus row A, the CEO's annual percentage salary increase in that same company. Suppose a random sample of companies yielded the following data:
B: Percent increase
for company   26   23   25   18   6   4   21   37
A: Percent increase
for CEO   21   25   22   14   −4   19   15   30
Do these data indicate that the population mean percentage increase in corporate revenue (row B) is different from the population mean percentage increase in CEO salary? Use a 5% level of significance. (Let d = B − A.)
(a) What is the level of significance?
0.05

Correct: Your answer is correct.

State the null and alternate hypotheses.
H0: μd = 0; H1: μd > 0
H0: μd = 0; H1: μd < 0
H0: μd ≠ 0; H1: μd = 0
H0: μd = 0; H1: μd ≠ 0
H0: μd > 0; H1: μd = 0
Correct: Your answer is correct.

(b) What sampling distribution will you use? What assumptions are you making?
The Student's t. We assume that d has an approximately uniform distribution.
The standard normal. We assume that d has an approximately normal distribution.
The Student's t. We assume that d has an approximately normal distribution.
The standard normal. We assume that d has an approximately uniform distribution.
Correct: Your answer is correct.

What is the value of the sample test statistic? (Round your answer to three decimal places.)

Answer 1