DigiSonic would also like to explore a more sophisticated forecasting method. They want you to consider exponential smoothing. a. Using simple exponential smoothing, compute three sets of forecasts for the sales of DigiSonic's Blu-Ray discs, corresponding to a values of 0.2, 0.5 and 0.8. Assume that the forecast for month 1 is 1376. (8pt) b. To visually see the difference between forecasts and actual demand, plot the actual demand as well as the three simple exponential smoothing forecasts computed in the same graph. Identify which value of a produces the most responsive forecast? What is the implication of this finding? (4pt) c. Calculate the MAE and Mean Absolute Percentage Error (MAPE) using the forecast errors for each of these three sets of forecasts. Which a value seems to be most appropriate and explain why. (3pt)