## Formula:

\begin{aligned} U_1 & = n_1n_2 + \frac{n_1(n_1+1)}{2}-R_1 U_2 & = n_1n_2 + \frac{n_2(n_2+1)}{2}-R_2 \end{aligned}

The test statistic is $U=min{U_1,U_2 }$.

The critical value of U is $U_{\alpha, n1,n2}$

Suggestions and comments will be appreciated.