Question

If you were going to do the t-test instead of the nonparametric test, would you use the results from the test assuming “unequal variance” or “equal variance”, and explain why.

Answer 1

The two versions of the test run different algorithms. There is a rule of thumb for the assumption of equality of variances that their ratio should be less than 4:1 (and thus the ration of standard deviations should be less than 2:1) for you to select the equal variances assumed version.

Shall you use the test for equal or unequal variances? If you have equal numbers of data points, or the numbers are nearly the same, then you should be able to safely use the two-sample test for equal variances

Completely dependent on data you have