Do a two-sample test for equality of means assuming equal variances. Calculate the p-value.
a. Comparison of GPA for randomly chosen college juniors and seniors: 1 = 3.05s s1 = .20, n1 = 15, 2 = 3.25, s2 = 30, n2 = 15, α = .025, left-tailed test.
b. Comparison of average commute miles for randomly chosen students at two community colleges: 1 = 15, s1 = 5, n1 = 22, 2 = 18, s2 = 7, n2 = 19, α =.05, two-tailed test.
c. Comparison of credits at time of graduation for randomly chosen accounting and economics students: 1 = 139, s1 = 2.8 n1 = 12, 2 = 137, s2 = 2.7, n2 = 17, α = .05, right-tailed test.