1. National scan, Inc., sells radio frequency inventory tags. Monthly sales for a seven-month period were as follows:
Month | Sales |
(units) | |
Feb | 19 |
Mar | 18 |
Apr | 17 |
May | 20 |
Jun | 19 |
Jul | 22 |
Aug | 20 |
- Forecast September sales volume using the naïve approach.
- Forecast September sales volume using a linear equation. a=17.43, b = 0.46.
- Forecast September sales volume using a five-month moving average
- Forecast September sales volume using a weighted average using .60 for August, .30 for July, and .10 for June.
- Forecast September sales volume using Exponential smoothing with a smoothing constant equal to .20, assuming a March forecast of 19.
2, A dry cleaner uses exponential smoothing to forecast equipment usage at its main plant. August usage was forecast to be 88 percent of capacity; actual usage was 89.6 percent of capacity. A smoothing constant (Alpha) of .2 is used.
a.Prepare a forecast for September.
b. Assuming actual September usage of 92 percent, prepare a forecast for October usage.
3. A cosmetics manufacturer’s marketing department has developed a linear trend equation that can be used to predict annual sales of its popular Hand & Foot Cream.
Ft =80+14t
Where
Ft Annual forecast in sales (bottles)
t= 0 corresponds to 1990
a. Predict annual sales for the year 2006 using the equation.
4.The manager of travel agency has been using a seasonally adjusted forecast to predict demand for packaged tours. The actual and predicted values are as follows:
Period | Demand | Predicted |
1 | 129 | 124 |
2 | 194 | 200 |
3 | 156 | 150 |
4 | 91 | 94 |
5 | 85 | 80 |
6 | 132 | 140 |
7 | 126 | 128 |
8 | 126 | 124 |
9 | 95 | 100 |
10 | 149 | 150 |
a. Compute MAD for the 5th period
b. Compute MAPE for the 10th period