Problem 3-31 A textbook publishing company has compiled data on total annual sales of its business texts for the preceding nine years: Year 1 2 3 4 5 6 7 8 9 Sales (000) : 37.10 45.00 49.80 51.00 54.60 57.60 63.40 68.80 74.90 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.) Year 10 11 12 13 14 Forecast 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.) Control limits are 0 + c. Suppose actual sales for the next five years turn out as follows: Year 10 11 12 13 14 Sales (000) : 78.60 82.40 88.90 92.00 96.90 Is the forecast performing adequately? O No O Yes