Harlen Industries has a simple forecasting model: Take the actual demand for the same month last year and divide that by the number of fractional weeks in that month. This gives the average weekly demand for that month. This weekly average is used as the weekly forecast for the same month this year. This technique was used to forecast eight weeks for this year, which are shown below along with the actual demand that occurred. The following eight weeks show the forecast (based on last year) and the demand that actually occurred: WEEK FORECAST DEMAND ACTUAL DEMAND 12345678 140 137 140 133 130 150 142 160 130 180 140 170 147 185 150 205 a. Compute the MAD of forecast errors. (Round your answers to 2 decimal places.) Week MAD 1 2 3 4 5 6 7 8 b. Using the RSFE, compute the tracking signal. (Round your answers to 2 decimal places. Negative values should be indicated by a minus sign.) Tracking Signal Week 1 2 3 4 5 6 7 8