Testing equality of variances.
Over the last several years, the use of cell phones has increased dramatically. According to a recent poll, the mean talking time per month for cell phones was 372 minutes for men and 275 minutes for women, while the mean talking time per month for traditional home phones was 334 minutes for men and 510 minutes for women.
Suppose that the poll was based on a sample of 100 men and 100 women, and that the standard deviation of talking time per month for cell phones was 120 minutes for men and 100 minutes for women, while the standard deviation of talking time per month for home phones was 110 minutes for men and 150 minutes for women. At the .05 level of significance, is there evidence of a difference in the variability of monthly talking time on cell phones for men and women?