<Dd> the sum of the ranks achieved by the hares is 11 + 10 + 9 + 8 + 7 + 1 = 46, leading to U = 46 − 21 = 25 . </Dd> <P> A second example race illustrates the point that the Mann--Whitney U test does not test for inequality of medians, but rather for difference of distributions . Consider another hare and tortoise race, with 19 participants of each species, in which the outcomes are as follows, from first to last past the finishing post: </P> <Dl> <Dd> HHHHHHHHHTTTTTTTTT T H HHHHHHHHHTTTTTTTTT </Dd> </Dl> <Dd> HHHHHHHHHTTTTTTTTT T H HHHHHHHHHTTTTTTTTT </Dd>

What is u in mann whitney u test