A problem with a telephone line that prevents a customer from receiving or making call is upsetting to both the customer and the telecommunications company. The following table contains samples of 20 problems reported to two different offices of a telecommunica tion company and the time to clear these problems (in minutes) from the customers lines. Office 1 1.48 1.75 0.78 2.85 0.52 1.60 4.15 3.97 1.48 3.10 1.02 0.53 0.93 1.60 0.80 1.05 6.32 3.93 5.45 0.97 Office 2 7.55 3.75 0.10 1.10 0.60 0.52 3.30 2.10 0.58 4.02 3.75 0.65 1.92 0.60 1.53 4.23 0.08 1.48 1.65 0.72 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 central offices? b) What assumption do you need to make in (a) about the two populations in order to justify your use of the F test?

4. a) = 1.2124 and = 2.5265 Not reject 0 b) The two populations are normally distributed How he found this answers?