why use non parametric mann-whitney U test rather than parametric independent sample test. I have a question regarding this because i just complete two question, as one I am using parametric tests, independent sample test, solve the mean selling price of a home with a conservatory different from the mean selling price of a home without conservatory. I also used non parametric tests, mann-whitney U test , these two test obtain the same result. can any one tell me why it's is most appropriate in testing the hypothesis using non-parametric mann-whitney U test? Thank you very much for your help. I will wait online.