Refer to the gasoline sales time series data in the given table.

Week Sales (1,000s of gallons)

1 17

2 21

3 19

4 23

5 18

6 16

7 20

8 18

9 22

10 20

11 15

12 22

Compute four-week and five-week moving averages for the time series.Do not round intermediate calculations. If required, round your answers to two decimal places.

Week Sales 4 wk moving avg. 5 wk moving avg.

1 17

2 21

3 19

4 23

5 18 _______________

6 16 ________________ ____________-

7 20 _______________ ___________

8 18 ______________ __________

9 22 ______________ ____________

10 20 ______________ ______________

11 15 _____________ _____________

12 22 ____________ ______________

(b)Compute the MSE for the four-week and five-week moving average forecasts.Do not round intermediate calculations. If required, round your answers to two decimal places.

MSE for four-week moving average =__________

MSE for five-week moving average =____________

What appears to be the best number of weeks of past data (three, four, or five) to use in the moving average computation? Consider that the MSE for the three-week moving average is 10.222.

Select from......Three, four, or five