Use the gasoline sales time series data from Table to show the exponential smoothing forecasts using = 0.1. Using the mean squared error criterion,

Use the gasoline sales time series data from Table to show the exponential smoothing forecasts using α = 0.1. Using the mean squared error criterion, would you prefer a smoothing constant of α = 0.1 or α = 0.2?
TABLE GASOLINE SALES TIMES SERIES
Week Sales (1000s 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