Two independent methods of forecasting based on judgment and experience have been prepared each month for the past 10 months. The forecasts and actual sales are as follows:
a. Compute the MSE and MAD for each forecast. Does either forecast seem superior? Explain.
b. Compute MAPE for each forecast.
c. Prepare a naive forecast for periods 2 through 11 using the given sales data. Compute each of the following; (1) MSE, (2) MAD, (3) tracking signal at month 10, and (4) 2s control limits. How do the naive results compare with the other two forecasts?