A$.$ Plot the demand for years $1$ to $4$ for both products $($Clear Plastic and Black Plastic$).$ What forecasting approaches do you recommend for predicting the demand for each product? Why? $(10\%)$

B$.$ Use Holt's model to forecast the quarterly demand for Clear Plastic for years $5$ and $6.$ What is the Mean Squared Error $($MSE$)$ for quarter $16?$ Calculate the values of the Tracking Signal $($TS$)$ for all quarters of years $1$ to $4$ and plot them. Is the forecast biased assuming the thresholds of $\backslash$pm $4?$ Why? $(30\%)$

C$.$ Apply Winter's model to forecast the quarterly demand of Black Plastic for years $5$ and $6$ assuming alpha$=0\mathrm{.}1,$ beta$=0\mathrm{.}1,$ and gamma$=0\mathrm{.}1.(30\%)$

D$.$ Optimize the values of the smoothing constants for the Black Plastic forecast based on the Mean Absolute Percentage Deviation $($MAPD$)$ value for quarter $16.$ When the smoothing factors in Winter$$s model are set to zero, the forecast will be the same as the result of which other forecasting model? $(30\%)$