Question:

Submit one excel file. Put each problem result on a separate sheet in your file. Please show all work/formulas in excel only!

10.45 A problem with a telephone line that prevents a customer from receiving or making calls is upsetting to both the customer and the telecommunications company. The file Phone contains communications company and the time to clear these problems (in minutes) from the customers' lines.

A. At the 0.05 level of significance, is there evidence of a difference in the variability of the time to clear problems between the two central offices?

b. Determine the p-value in (a) and interpret its meaning.

c. What assumption do you need to make in (a) about the two populations in order to justify your use of the F test?

d. Based on the results of (a) and (b), which t test should you use to compare the mean time to clear problems in the two central offices?