Consider the Prediction Equation $\hat { y }$ = 604 + 010(t)and the Data Below

Consider the prediction equation $\hat { y }$ = 6.04 + 0.10(t)and the data below. $$\begin{array} { c c } \text { Time period } & \text { Sales (y) } \\1 & 6.1 \\2 & 6.0 \\3 & 6.1 \\4 & 6.3 \\5 & 6.8 \\6 & 6.8 \\7 & 7.0 \\8 & 7.1 \\9 & 7.0 \\10 & 7.1 \\11 & 6.8 \\12 & 7.0 \\13 & 7.2 \\14 & 7.4 \\15 & 7.5\end{array}$$
-Compute the forecast errors for period 7 and period 8.