An article appearing in The Exponent, an independent college newspaper published by the Purdue Student Publishing Foundation, reported that the average American college student spends one hour (60 minutes) on Face-book daily. (Data extracted from bit.ly/NQRCJQ.) But you wonder if there is a difference between males and females. You select a sample of 60 Facebook users (30 males and 30 females) at your college. The time spent on Face-book per day (in minutes) for these 60 users is stored in FacebookTime2
a. Assuming that the variances in the population of times spent on Facebook per day are equal, is there evidence of a difference in the mean time spent on Facebook per day between males and females? (Use a 0.05 level of significance.)
b. In addition to equal variances, what other assumption is necessary in (a)?