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:

Month	Sales	Forecast 1	Forecast 2
1	835	790	805
2	840	795	825
3	835	820	815
4	845	835	855
5	795	780	785
6	830	780	801
7	815	780	785
8	860	820	815
9	815	830	845
10	845	835	835

a. Compute the MSE and MAD for each forecast. (Round your answers to 2 decimal places.)

b. Compute MAPE for each forecast. (Round your intermediate calculations to 5 decimal places and final answers to 4 decimal places.)

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. (Negative values should be indicated by a minus sign. Round your answers to 2 decimal places.)