Table $9.($see Excel file Ex$9)$

Lubricating Oil Production

$9\mathrm{.}1.$ Develop a three$-$month simple moving average forecasting model. $(1$pt$)$

$9\mathrm{.}2.$ Develop a three$-$month weighted moving average using a factor of $0\mathrm{.}6$

for the most recent period.

$0\mathrm{.}2$ for the next period and $0\mathrm{.}2$ for the oldest period. $(1$pt$)$

$9\mathrm{.}3.$ Using the concept of the mean absolute deviation $($MAD$),$

which model is preferred? $(1$pt$)$

$9\mathrm{.}4.$ Use the preferred model to forecast the lube oil requirements

for the following January.$(1$pt$)$