Specify the test statistic and the rejection region for the Wilcoxon rank sum test for independent samples in each of the following situations:

a. n1 = 10, n2 = 6, a = .10 H0: Two probability distributions, 1 and 2, are identical Ha: Probability distribution for population 1 is shifted to the right or left of the probability distribution for population 2

b. n1 = 5, n2 = 7, a = .05 H0: Two probability distributions, 1 and 2, are identical Ha: Probability distribution for population 1 is shifted to the right of the probability distribution for population 2

c. n1 = 9, n2 = 8, a = .025 H0: Two probability distributions, 1 and 2, are identical Ha: Probability distribution for population 1 is shifted to the left of the probability distribution for population 2

d. n1 = 15, n2 = 15, a = .05 H0: Two probability distributions, 1 and 2, are identical Ha: Probability distribution for population 1 is shifted to the right or left of the probability distribution for population 2