I have two groups with equal variances and unequal sample size (28 and 8) and I want to run a Student t-test. Can I use Mann-Whitney considering that the variances are equal? Do you think if there is a better test to compare the samples?
Best Answer
Theoretically, if the assumption of equal variances is satisfied and the dependent variable is normally distributed you could run a t-test despite the unequal sample sizes between the two comparison groups. I suggest you read these two posts (1 & 2) which deal with similar issues. If the assumption of normality is not satisfied then a Mann-Whitney test is appropriate as you have already suggested. You don't provide more information regarding your research questions and data availability to actually recommend a better statistical test.
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