4. The owner of a small brewery in Milwaukee, Wisconsin, is using Winter's method to

forecast his quarterly beer sales. He has been using smoothing constant of a = 0.2, ß = 0.2,

and y = 0.3. He has currently obtained the following values of the various slope, intercept,

and seasonal factors:

S1o = 120, G10 =14

C10 = 1.2, C9 = 1.1, c8 = 0.8, and c7 = 0.9

a. Determine the forecast for beer sales in quarter 10.

b. Suppose that the actual sales turn out to be 128 in quarter 10. Find S11 and G11, and find

the updated value of the seasonal factor.

c. Using results in (b), determine the forecast made at the end of quarter 10 for quarter 12.