The following forecasts were calculated using the 3 month simple moving average approach. Calculate the error for April through September forecasts, and then calculate the MAD (mean absolute deviation). What is the MAD for this set of demand and forecast data? Question 5 Assume that your stock of sales merchandise is maintained based on the forecast demand. If the distributor's sales personnel call on the first day of each month, compute your forecast sales for SEPTEMBER. Use the 3 period weighted moving average approach, with weights of 50 for the most recent month, 30 for the second month, and 20 for the oldest month's demand data