$\backslash$table$[[$WEEK OF$,$PINTS USED$],[$August $31,360],[$September $7,389],[$September $14,410],[$September $21,381],[$September $28,368],[$October $5,374]]$

$\mathrm{.}4\mathrm{.}16$ Refer to Solved Problem $4\mathrm{.}1.$

a$.$ Using the trend$-$projection $($regression$)$ method, develop a forecast for the sales of Volkswagens in Nevada through year $6.$

b$.$ What is the MAD? $[$PX$]$

c$.$ What is the MSE?

$\mathrm{.}4\mathrm{.}17$ Refer to Solved Problem $4\mathrm{.}1.$ Using smoothing constants of $.6$ and $\mathrm{.}9,$ develop forecasts for the sales of Volkswagens. What effect did the smoothing constant have on the forecast? Use MAD to determine which of the three smoothing constants $,$ or $\mathrm{.}9)$ gives the most accurate forecast. $[$PX$]$