Problem $3$: For the data in the Excel file Airport Passengers, do the following:

a$.$

Develop a spreadsheet for forecasting the number of airport passengers using simple exponential smoothing with smoothing constants $()$ from $0\mathrm{.}1$ to $0\mathrm{.}9$ in increments of $0\mathrm{.}2.$

b$.$

Using MSE as guidance, find the best smoothing constant.

c$.$

Find the forecast for the next week.