Assume 35 office workers are randomly selected, and the mean time they spent on browsing the web on their work computers is 27.8 minutes, and the standard deviation is 8.2 minutes.

a. (10 points)

Test the claim that the population mean time office workers spend on browsing the web on their work computers is more than 25 minutes. Let the significance level be 0.05.

H₀ :

H₁ :

Critical number(s) =

Round the same as the critical number(s). Test statistic =

H₀

There sufficient evidence to the claim that the population mean time office workers spend on browsing the web on their work computers is more than 25 minutes.

b. Find the 99% confidence interval estimating the population mean time office workers spent on browsing the web on their work computers. Use "<" for the confidence interval. (10 points)

Value from the appropriate table =

Round answers to one decimal place. Include units. Confidence interval=