Assignment 8 eBook Problem 15-07 (Algorithmic) Refer to the gasoline sales time series data in the given table. Week Sales (1000s of gallons) 1 17 2 21 3 18 4 24 5 17 6 15 7 21 8 17 9 23 10 21 11 15 12 22 a. Compute four-week and five-week moving averages for the time series. Round your answers to two decimal places. 4-Week Moving Average 5-Week 5- Moving Average Week Sales 1 17 2 21 3 3 18 4 4 24 5 17 6 6 15 TTTTTTTT 7 21 8 17 9 23 10 21 11 15 12 22 b. 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 = = c. 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 14.98