21.3 As we have done in the previous two exercises, we bring forward from the previous chapter a single linear regression problem and add an additional variable. In that exercise, you had one independent variable, which was “the number of times an individual attended church during a month.” For this current exercise, you will add another independent variable, which is “the number of times one prays in a day.”

The deacon of the church wants to see if the earlier prediction equation could be improved by adding this additional variable. As before, he wants to compare the performance of the new equation with the actual observed values. In addition, he wishes to predict the number of volunteer hours for those rated as average on the two independent variables. Use multiple linear regression, write the null and alternative hypotheses, do the analysis, and interpret the results. The deacon’s new data are as follows: