Task $1$: Run Forecast $(13$ points$)$

For each of the following forecasting approaches, calculate forecast.

a$.$ Na$$ve method.

b$.$ Three$-$period moving average method.

c$.$ Exponential smoothing. Use Excel's Solver to determine the value of alpha that minimizes MAD for

period $4-11.($Hint: when running Solver, use an initial alpha value of $\mathrm{.}5)$

d$.$ Linear trend $($i$.$e$.,$ regression$).$