In: Physics
            Compute four-week and five-week moving averages for the time series. Round your answers to two decimal places.
                
            
 
Refer to the gasoline sales time series data in the given table.
| Week | 
Sales (1000s of gallons) | 
| 1 | 
18 | 
| 2 | 
21 | 
| 3 | 
19 | 
| 4 | 
22 | 
| 5 | 
18 | 
| 6 | 
16 | 
| 7 | 
20 | 
| 8 | 
19 | 
| 9 | 
23 | 
| 10 | 
19 | 
| 11 | 
16 | 
| 12 | 
22 | 
- Compute four-week and five-week moving averages for the time series. Round your answers to two decimal places.
 Week | 
 Sales | 
4-Week Moving Average | 
5-Week Moving Average | 
| 1 | 
18 | 
  | 
  | 
| 2 | 
21 | 
  | 
  | 
| 3 | 
19 | 
  | 
  | 
| 4 | 
22 | 
  | 
  | 
| 5 | 
18 | 
  | 
  | 
| 6 | 
16 | 
  | 
  | 
| 7 | 
20 | 
  | 
  | 
| 8 | 
19 | 
  | 
  | 
| 9 | 
23 | 
  | 
  | 
| 10 | 
19 | 
  | 
  | 
| 11 | 
16 | 
  | 
  | 
| 12 | 
22 | 
  | 
  | 
 
- 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 9.