$9.$ Forecasting Gasoline Sales with Exponential Smoothing. With the gasoline time series data from Table $15\mathrm{.}1,$ show the exponential smoothing forecasts using a $50\mathrm{.}1.$ LO $1,3$ a$.$ Applying the MSE measure of forecast accuracy, would you prefer a smoothing constant of a $50\mathrm{.}1$ or a $50\mathrm{.}2$ for the gasoline sales time series?$$b$.$ Are the results the same if you apply MAE as the measure of accuracy? c$.$ What are the results if MAPE is used?