Sales (In Thousands)of the New Thorton Model 506 Convection Oven

Essay

Sales (in thousands)of the new Thorton Model 506 convection oven over the eight-week period since its introduction have been as follows: $$\begin{array} { c c } \text { Week } & \text { Sales } \\\hline 1 & 18.6 \\2 & 21.4 \\3 & 25.2 \\4 & 22.4 \\5 & 24.6 \\6 & 19.2 \\7 & 21.7 \\8 & 23.8\end{array}$$
a.Which exponential smoothing model provides better forecasts, one using  = .6 or  = .2? Compare them using mean squared error.
b.Using the two forecast models in part (a), what are the forecasts for week 9?