This is a repost as the individual who answered this on the other submission provided some incorrect answers.

The U.S. monthly inflation rate for 2020 is shown below: places. Forecast (January 2021, a=0.8 ): % Forecast (January 2021, a=0.9 ): % MAD(a=0.8) : (3)p.p. MAD(a=0.9) : p.p. Which method is better? The exponential smoothing with a smoothing constant of is better because it provides a MAD