The Excel file Closing Stock Prices provides data for four stocks and the Dow Jones Industrial Average over a one$-$month period.

a$.$ Develop a spreadsheet model for forecasting each of the stock prices using simple exponential smoothing with a smoothing constant of $0\mathrm{.}3.$

b$.$ Compare your results to the output from Excel's Data Analysis tool.

c$.$ Compute MAD, MSE, and MAPE.

d$.$ Does a smoothing constant of $0\mathrm{.}1$ or $0\mathrm{.}5$ yield better results? Please include all formulas