# Are my assumptions right for this question?

I answered these homework questions but I was told that at least one of my answers is wrong. However, I can't tell which one I answered wrong. What incorrect assumptions have I made?

QUESTION:

3a) Welch's T-test would be most appropriate since we have normal data with unequal variances.

3b) A Wilcoxon-Mann Whitney U Test appears to be the best option since transformations have failed and we must now use a non-parametric test for these 2 independent samples.

3c) The data has unequal variances and is not normal so we should also use a Wilcoxon-Mann Whitney U Test here too.

• In (c), consider the interpretation of "p-values > $\alpha$" (not that I agree with the reasoning behind these questions). – mark999 Nov 16 '16 at 5:23
• I believe I did. When p > α in Levene's test, there are unequal variances. When p > α in the Shapiro-Wilk test, the distribution is not normal. Or am I incorrect? – orangebull Nov 16 '16 at 5:35
• en.wikipedia.org/wiki/Levene%27s_test – mark999 Nov 16 '16 at 5:39
• If they really will not tell you which one is wrong you might consider changing course and asking for your money back. – mdewey Nov 16 '16 at 12:25

When the p-value is large the null should not be rejected. In significance testing, the null hypothesis is rejected when the p-value is smaller than the significance level ($\alpha$).