The owner of a small brewery in Milwaukee, Wisconsin, is using Winters’s method to forecast his quarterly beer sales. He has been using smoothing constants of

  .2,   .2, and   .2. He has currently obtained the following values of the various slope, intercept, and seasonal factors: S10  120, G10  14, c10  1.2, c9  1.1, c8  .8, and c7  .9.

a. Determine the forecast for beer sales in quarter 11.

b. Suppose that the actual sales turn out to be 128 in quarter