Problem: Monthly sales for National Mixer, Inc. for a seven-month period were as follows:
Month (T) - Sales (1000 UNITS)
Feb - 19
Mar - 18
Apr - 15
May - 20
Jun - 18
Jul - 22
Aug - 20
Forecast the sales volume for September using each of the following method:
1) 5-month moving average;
2) Weighted average, where the weights are - 0.60 (August), 0.30 (July), 0.10 (June)
3) Exponential smoothing with a smoothing constant equal to 0.20
4) Linear trend equation, Y = 16.86+0.5*T;