$($c$)$

Use $=0\mathrm{.}2$ to compute the exponential smoothing values for the time series.

Week Time Series

Value Forecast

$119$

$213$

$19$

$($e$)$

Use trial and error to find a value of the exponential smoothing coefficient $$ that results in a smaller MSE than what you calculated for $=0\mathrm{.}2.$

$=$