A firm producing photochemical has a weekly demand pattern as shown in Table 5.17. Using a smoothing constant of = 0.5 for both original data and trend, and beginning with week I,

(a) compute the simple exponentially smoothed forecast and

(b) compute the trend-adjusted exponentially smoothed forecast for the first five periods.

Table 5.17 Week 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Demand 30 34 22 16 10 10 14 20 30 36 30 10 12 20 30