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Problem 15-07 (Algorithmic) Refer to the gasoline sales time series data in the

ID: 369598 • Letter: P

Question

Problem 15-07 (Algorithmic)

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

Compute four-week and five-week moving averages for the time series. Round your answers to two decimal places.

Compute the MSE for the four-week and five-week moving average forecasts. Round your intermediate calculations and final 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? Recall that MSE for the three-week moving average is 11.98. Three / Four / Five

Week Sales (1000s of gallons) 1 18 2 22 3 19 4 22 5 19 6 15 7 22 8 18 9 22 10 19 11 14 12 22

Explanation / Answer

The four week moving average

Five week moving average,

Since the 5 Year Moving average MSE is the least,

It is best to take 5 years of past data.

Year Actuals 4Y MA Abs Error Sq Error 1 18 2 22 3 19 4 22 5 19 20.25 1.25 1.5625 6 15 20.50 5.50 30.25 7 22 18.75 3.25 10.5625 8 18 19.50 1.50 2.25 9 22 18.50 3.50 12.25 10 19 19.25 0.25 0.0625 11 14 20.25 6.25 39.0625 12 22 18.25 3.75 14.0625 MSE 13.75781