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

Year:	1	2	3	4	5	6	7	8
Sales(000):	37.80	43.20	49.00	50.50	54.50	58.90	63.20	68.30

a-1. Select the correct data chart and fit an appropriate model to it.

Chart A	Chart B	Chart C

(Click to select) Chart A Chart B Chart C

a-2. Forecast the preceding eight years, and determine the forecast errors. (Negative answers should be indicated by a minus sign. Do not round intermediate calculations and round your final answer to 2 decimal places.)

Year	Sales(000)	Forecast	Error	Error2
1	37.80
2	43.20
3	49.00
4	50.50
5	54.50
6	58.90
7	63.20
8	68.30

a-3. Construct 2s control limits. (Round the final answer to 2 decimal places.)

2s control limits are

b. Using the model, forecast textbook sales for each of the next five years. (Round the final answers to 1 decimal place.)

Year	Sales(000)	Forecast	Error
9	74.40
10	77.30
11	82.90
12	88.60
13	93.90

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

Year:	9	10	11	12	13
Sales(000):	74.40	77.30	82.90	88.60	93.90

Calculate the forecast errors for years 9 to 13. Is the forecasting process in control? (Click to select) Yes No