Smoothing

$5.$ Now improve your forecast with exponential smoothing. The same Gasoline data also exist in Test $4$ Applied Data.x$/$sx on the tab Smoothing. Compute the measures of forecast accuracy using a smoothing constant of $=0\mathrm{.}1$ or $=0\mathrm{.}2$ for the gasoline sales time series. $($Remember Excel's dampening factor is the inverse of alpha$)$