Given the following demand data, use exponential smoothing to forecast the demand in time period 13.

Time 1 2 3 4 5 6 7 8 9 10 11 12
Demand 105 82 111. 109 94. 99 117 116 103 96 89 103
a) Use the average over the 12 time periods as the initial estimate (S0) and try different