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 elght weeks show the forecast (based on last year) and the demand that actually occurred: FORECAST WEEK DEMAND ACTUAL 1 2 4 5 DEMAND 150 140 145 145 155 165 145 144 147 143 155 165 185 175 190 210 7 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