Data collected on the yearly demand for 50-pound bags of fertilizer at Wallace Garden Supply are shown in the following table.

Year Demand for fertilizer

(1,000s of bags)

1 4

2 6

3 4

4 5

5 10

6 9

7 10

8 11

9 15

10 16

11 18

1. Develop a 3-year moving average to forecast sales.

2. Then estimate demand again with a weighted moving average in which sales in the most recent year are given a weight of 3 and a weight of 2 for the second past year and sales in the other 2 years are each given a weight of 1.

3. Which method do you think is best?

4. Develop a trend line for the demand for fertilizer using any computer software.

5. You have now developed three different forecasts. These are a3-year moving average, a weighted moving average, and a trend line. Which one would you use? Explain your answer.