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):	38.20	43.10	47.80	53.20	56.20	59.70	60.90	69.50	74.00

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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

Forcast:

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:

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

Year	10	11	12	13	14
Sales (000):	78.10	84.40	88.10	91.70	97.50

Is the forecast performing adequately?

multiple choice

• Yes

• No