Question

Suppose these data show the number of gallons of gasoline sold by a gasoline distributor in Bennington, Vermont, over the past 12 weeks.

Week	Sales (1,000s of gallons)
1	17
2	22
3	20
4	24
5	18
6	17
7	21
8	19
9	23
10	21
11	16
12	22

(a) Compute four-week and five-week moving averages for the time series.

Week	Time Series Value	4-Week Moving Average Forecast	5-Week Moving Average Forecast
1	17
2	22
3	20
4	24
5	18
6	17
7	21
8	19
9	23
10	21
11	16
12	22

(b) Compute the MSE for the four-week moving average forecasts. (Round your answer to two decimal places.)

Compute the MSE for the five-week moving average forecasts. (Round your answer to two decimal places.)

Answer 1

a)

			4 period	5 period
week	time series		forecast	forecast
1	17
2	22
3	20
4	24
5	18		20.75
6	17		21.00	20.2
7	21		19.75	20.2
8	19		20.00	20
9	23		18.75	19.8
10	21		20.00	19.6
11	16		21.00	20.2
12	22		19.75	20.00

b)

MSE for the four-week moving average forecasts =-9.41

MSE for the five-week moving average forecasts =6.53