Experian Marketing Services reported that the typical American spends 144 minutes (2.4 hours) per day accessing the Internet through a mobile device. You wonder if males and females spend differing amounts of time per day accessing the Internet through a mobile device. You select a sample of 60 friends and family (30 males and 30 females), collect times spent per day accessing the Internet through a mobile device (in minutes), and store the data collected in InternetMobileTime2. 

a. Using a 0.05 level of significance, is there evidence of a difference in the variances of time spent per day accessing the Internet via mobile device between males and females? 

b. On the basis of the results in (a), which t test defined in Section 10.1 should you use to compare the means of males and females? Discuss.