Question

Please tell me which test would be best to use in a nonparametric test of hypothesis for (is the average income of men and women greater than 30000).

Here are the tests:
Kruskal-Wallis
Mann-Whitney

Answer 1

Kruskal-Wallis is the nonparametric counterpart of the one-way between subjects ANOVA. Mann-Whitney is the nonparametric counterpart of the independent groups t-test.