This applet computes probabilities for the Mann-Whitney $U$ Test. The Mann-Whitney statistic $U$ is the number of pairs $(X_i, Y_j)$ where $X_i > Y_j$.

Directions

• Enter $n_1$ and $n_2$ (total $n \le 30$ for exact calculations).
• The plot shows the probability mass function (pmf) of $U$ under $H_0$.