A textbook publishing company has compiled data on total annual sales of its business texts for the preceding nine years:

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.)

1	2	3	4	5	6	7	8	9
37.50	43.60	49.10	51.80	54.20	58.50	62.10	69.20	74.60

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.)

c. Suppose actual sales for the next five years turn out as follows:

Year	10	11	12	13	14
Sales (000):	78.20	81.30	88.40	91.00	96.50

Is the forecast performing adequately?