Solve the problem.

In any production process in which one or more workers are engaged in a variety of tasks, the total time spent in production varies as a function of the size of the workpool and the level of output of the various activities. In a large metropolitan department store. it is believed that the number of manhours worked $(y)$ per day by the clerical staff depends on the number of pieces of mail processed per day $(x_1)$ and the number of checks cashed per day $(x_2).$ Data collected for $n=20$ working days were used to fit the model:

$E(y)={}_O+{}_1{x}_1+{}_2{x}_2$

A partial printout for the analysis follows:

Parameter Estimates

$\backslash$table$[[,,$PARAMETER,STANDARD,TFORO:,$],[$VARIABLE$,$DF$,$ESTIMATE,ERROR,PARAMETER $=0,$PROB$>>|T|$