1. In a study of the ways in which college students who use Facebook differ from college students who do not use Facebook, each person in a sample of 141 college students who use Facebook was asked to report his or her college grade point average (GPA). College GPA was also reported by each person in a sample of 68 students who do not use Facebook. The researchers were hoping to determine whether the mean college GPA for students who use Facebook is lower than the mean college GPA of students who do not use Facebook. The two samples were independently selected from students at a large South African university. Although the samples were not selected at random, they were selected to be representative of the two populations (students who use Facebook and students who do not use Facebook at this university). Data from these samples were used to compute sample means and standard deviations, reported in the table below: Sample Standard Population Population Mean Sample Size Sample Mean Deviation Students at the university My = mean college GPA 1 = 141 X1 = 3.06 $1 = 0.95 who use Facebook for students who use Facebook Students at the university H2 = mean college GPA n2 - 68 X2 - 3.82 $2 - 0.41 who do not use Facebook for students who do not who use Facebook a) Use a hypothesis test to determine, at a 0.05 level of significance, whether these data provide evidence that the mean GPA for students who use Facebook is lower than the mean GPA for students who do not use Facebook. i. Use the critical value approach. ii. Use the p-value approach. b) Construct a 90% confidence interval for the difference between the GPA scores for the Facebook and non-Facebook users, and interpret this interval