need help with attached question . I have attached the question. please show how you came up with the answer .

-2-2 http://ezto.mhedu Do a two-sample test for equality of means assuming unequal variances. Calculate the p-value using Excel. (a) Comparison of GPA for randomly chosen college juniors and seniors: = 3.05, s1 = .20, n1 = 15, = 3.25, s2 = .30, n2 = 15, = .025, left-tailed test. (Negative values should be indicated by a minus sign. Round your d.f. answer to the nearest whole number and other answers to 4 decimal places. Do not use "quick" rules for degrees of freedom.) d.f. t-calculated p-value t-critical (b) Comparison of average commute miles for randomly chosen students at two community colleges: = 15, s1 = 5, n1 = 22, = 18, s2 = 7, n2 = 19, = .05, two-tailed test. (Negative values should be indicated by a minus sign. Round your d.f. answer to the nearest whole number and other answers to 4 decimal places. Do not use "quick" rules for degrees of freedom.) d.f. t-calculated p-value t-critical (C) Comparison of credits at time of graduation for randomly chosen accounting and economics students: = 139, s1 = 2.8, n1 = 12, = 137, s2 = 2.7, n2 = 17, = .05, right-tailed test. (Negative values should be indicated by a minus sign. Round your d.f. answer to the nearest whole number and other answers to 4 decimal places. Do not use "quick" rules for degrees of freedom.) d.f. t-calculated p-value t-critical