Do males and females differ in the amount of time they spend online and the amount of time they spend playing games while online? A study reported that women spent a mean of 1,068 minutes per week online as compared to 1,398 minutes per week for men. (Data extracted from Ofcom, Adults' Media Use and Attitudes Report, 2015.) The sample sizes were not reported. Suppose that the sample sizes were 100 each for women and men and that the standard deviation for women was 50 minutes per week as compared to 75 minutes per week for men.

a. Using a 0.01 level of significance, is there evidence of a difference in the variances of the amount of time spent online between women and men?

b. To test for a difference in the mean online time of women and men, is it most appropriate to use the pooled-variance t test or the separate-variance t test? Use the most appropriate test to determine if there is a difference in the mean amount of time spent online between women and men. The article also reported that women spent a mean of 276 minutes per week playing games while online compared to 396 minutes per week for men. Suppose that the standard deviation for women was 15 minutes per week compared to 20 minutes per week for men.

c. Using a 0.01 level of significance, is there evidence of a difference in the variances of the amount of time spent playing games while online per week by women and men?

d. Based on the results of (c), use the most appropriate test to determine, at the 0.01 level of significance, whether there is evidence of a difference in the mean amount of time spent playing games online per week by women and men.