Using techniques from an earlier section, we can find a confidence interval for_d. Consider a random sample ofnmatched data pairsA,B. Letd=BAbe a random variable representing the difference between the values in a matched data pair. Compute the sample meand

of the differences and the sample standard deviations_d. Ifdhas a normal distribution or is mound-shaped, or ifn30, then aconfidence intervalfor_dis as follows.dE<_d<d+E

whereE=t_cs_d

n

c= confidence level (0 <c< 1)

t_c= critical value for confidence levelcandd.f. =n1

B: Percent increase

for company8183018642137A: Percent increase

for CEO181915144

191530

(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 limitupper limit

(b) Use the confidence interval method of hypothesis testing 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.

Since_d= 0 from the null hypothesis is not in the 95% confidence interval, do not rejectH₀at the 5% level of significance. The data indicate a difference in population mean percentage increases between company revenue and CEO salaries.

Since_d= 0 from the null hypothesis is not in the 95% confidence interval, rejectH₀at the 5% level of significance. The data indicate a difference in population mean percentage increases between company revenue and CEO salaries.

Since_d= 0 from the null hypothesis is in the 95% confidence interval, do not rejectH₀at the 5% level of significance. The data do not indicate a difference in population mean percentage increases between company revenue and CEO salaries.

Since_d= 0 from the null hypothesis is in the 95% confidence interval, rejectH₀at the 5% level of significance. The data do not indicate a difference in population mean percentage increases between company revenue and CEO salaries.