b. Compute +/- 2s control limits for the control chart for forecast errors using just data from the original nine periods. (Round your intermediate calculations to 4 decimal places and final answer to 2 decimal places.)

Problem 3-31 A textbook publishing company has compiled data on total annual sales of its business texts for the preceding nine years: Year Sales (608): 1 38.30 2 44.10 4 50.90 5 54.70 6 57.48 7 64.ee 8 69.50 9 74.60 48.90 a. Using an appropriate model, forecast textbook sales for each of the next five years. (Round your Intermediate calculations to 3 decimal places and final answers to 2 decimal places.) 10 11 12 13 14 Year Forecast 77.33 8164 85.94 90.24 94.54 b. Compute +/- 2s control limits for the control chart for forecast errors using just data from the original nine periods. (Round your Intermediate calculations to 4 decimal places and final answer to 2 decimal places.) Controllimits are 0 c. Suppose actual sales for the next five years turn out as follows: Year Sales (808): le 77.00 11 82.99 12 87.2e 13 92.10 14 98.10 Is the forecast performing adequately? O Yes No