$1-$ Using the data in following table,

a$)$ Compute a $3-$month moving forecast of Sales from April through December and for the next month,

January. Compute the MAD for the forecast.

b$)$ Compute a $6-$month moving forecast of Sales from July through December and for the next month,

January. Compute the MAD for the forecast.

c$)$ Compute a weighted $3-$month moving forecast of Sales from April through December and for the next

month, January, using weights of $0\mathrm{.}50($most recent data$),0\mathrm{.}30,$ and $0\mathrm{.}20($most distant data$).$ Compute

the MAD for the forecast.

D$)$ Compare the forecasts you computed by using moving forecast model from part a$,$ b$,$ and c$.$ Which

forecasting model does a better job?