please answer A & B

Problem 3-20 (Algo) In this problem, you are to test the validity of your forecasting model. Here are the forecasts for a model you have been using and the actual demands that occurred: FORECAST ACTUAL WEEK 1 750 845 2 795 945 3 895 995 4 895 845 5 945 845 920 990 a. Use the method stated in the text to compute the MAD and tracking signal for each week. (Negative values should be indicated by a minus sign. Round your "Tracking Signal" to 2 decimal place and all other answers to the nearest whole number.) Week Forecast Actual Deviation Sum of Absolute RSFE Absolute Deviation MAD TS Deviation 1 750 845 2 795 945 895 995 895 845 945 845 920 990 3 | 4 5 in D 6 b. Decide whether the forecasting model you have been using is giving reasonable results. O The forecasting model is unacceptable The forecasting model is acceptable WEEK 123456 FORECAST 750 795 895 895 945 920 ACTUAL 845 945 995 845 845 990