If the $n=20$ values of processing time mentioned in Example 7.1 .2 are $16.39,25.09,16.31,20.94,17.58,19.06,17.21,18.48,16.88$, $15.51,25.87,17.63,29.13,21.34,11.14,26.03,23.28,21.13,18.46$, 14.25 , find the method of moments estimates of $\beta$ and $\alpha$.