Use the Mann-Whitney test to test the given hypotheses at the a = 0.05 level of significance. The independent samples were obtained randomly.
1. Hypotheses: H0: Mx = My versus H1: Mx ≠ My with n1 = 12, n2 = 15, and S = 170
2. Hypotheses: H0: Mx = My versus H1: Mx ≠ My with n1 = 10, n2 = 8, and S = 100
3. Hypotheses: H0: Mx = My versus H1: Mx < My with n1 = 18, n2 = 16, and S = 210