a$)$ Plot the time series data and comment on the pattern you observe.

b$)$ Use weighted moving average method to forecast the demand for $2017.$

c$)$ Use exponential smoothing with optimal $\backslash$alpha to forecast the demand for $2017.$

d$)$ Use regression method to forecast the demand for $2017-2020.$

e$)$ Compute the following measures of forecast accuracy: mean absolute error $($MAE$),$ mean

squared error $($RMSE$),$ mean absolute percentage error $($MAPE$)$ for your forecasts in

parts b$,$ c and d$.$

f$)$ Determine the most accurate forecast method and estimate the demand for $2017.$