Problem Igo) A particular forecasting model was used to forecast a six-month period. Here are the forecasts and actual demands that resulted April May June July August September FORECAST 250 325 400 350 375 ACTUAL 198 232 318 292 317 390 o. Find the tracking signal for each month (Negative values should be indicated by a minus sign. Round your answers to the 2 decimal places.) Tracking Signal Month April May June July August September b. is the model being used is giving acceptable answers. No, the model's performance is poor Yes, the model's performance is good. Problem 3-29 (Algo) Mark Price, the new productions manager for Speakers and Company, needs to find out which variable most affects the demand for their line of stereo speakers. He is uncertain whether the unit price of the product or the effects of increased marketing are the main drivers in sales and wants to use regression analysis to figure out which factor drives more demand for its particular market. Pertinent information was collected by an extensive marketing project that lasted over the past 12 years and was reduced to the data that follow YEAR 1 2 3 4 5 6 7 8 9 1e 11 12 UNIT SALES (THOUSANDS) 375 675 875 1,296 1,148 1,175 875 1,106 972 1,239 874 805 PRICE $/UNIT 279 220 217 206 220 194 221 203 226 217 221 248 ADVERTISING (5000) 616 830 1,106 1,403 1,204 1,296 874 1,106 695 874 695 695 a. Perform a regression analysis based on these data using Excel. (Negative values should be indicated by a minus sign. Round your answers to 4 decimal places.) y bar = Price advertising c. Predict average yearly speaker sales for Speakers and Company based on the regression results if the price was $275 per unit and the amount spent on advertising (in thousands) was $875. (Enter your answer in thousands. Round your intermediate calculations and final answer to 2 decimal places.) Forecasted sales thousand units