A retail store reports the following monthly sales: Month Sales (thousands of dollars) 1. Compute a 3 month moving average forecast and a 5 month moving average forecasts for months 8 through 17. 2. Compute the mean absolute deviation (MAD) for the two forecasts based upon months 8 through 17 and determine which forecast is more accurate. 3. Based upon the more accurate forecast, compute the forecast for month 18