For a study of statistics students, the prediction equation relating \(y=\) final grade (as score), to \(x_{1}=\) midterm grade (as score) and \(x_{2}=\) number of classes missed is \(\hat{y}=46.39+0.54 x_{1}-4.90 x_{2}\).

a. Find the predicted total final grade for a statistics student at the mean values of 96 and 1 for \(x_{1}\) and \(x_{2}\).

b. A statistics student with \(x_{1}=96\) and \(x_{2}=1\) has actual final grade \(y=78\). Find the residual and interpret it.