Firm ABC observes the demand of its product Z over 10 periods as follow: Requirements: a) Assume an initial forecast of 100 units. Plot a line chart showing the actual demand, the forecast with =0.2, the forecast with =0.8 over the 10 periods. Comment on the chart patterns. [Suggestion: Use MS Excel to plot the THREE (3) lines. Copy and paste the chart onto the MS Word report.] b) Compute the Mean Absolute Deviations (MAD) for both =0.2&0.8 during periods 1 to 10. Tabulate your answers. c) Comment on the MAD results obtained in part (b). Which value would you recommend using for the next period of forecasting? Justify