The paper “Facebook Use and Academic Performance Among College Students: A Mixed- Methods Study with a Multi-Ethnic Sample” (Computers in Human Behavior [2015]: 265–272) describes a survey of a sample of 66 male students and a sample of 195 female students at a large university in Southern California. The authors of the paper believed that these samples were representative of male and female college students in Southern California. For the sample of males, the mean time spent per day on Facebook was 102.31 minutes. For the sample of females, the mean time was 159.61 minutes. The sample standard deviations were not given in the paper, but for purposes of this exercise, suppose that the sample standard deviations were both 100 minutes.

a. Do the data provide convincing evidence that the mean time spent on Facebook is not the same for males and for females? Test the relevant hypotheses using a = 0.05.

b. Do you think it is reasonable to generalize the conclusion from the hypothesis test in Part (a) to the populations of all male college students in the United States and all female college students in the United States? Explain why you think this.