Sales of tennis rackets over the last five months at a local sports center are

Sales of tennis rackets over the last five months at a local sports center are shown below

month sales

1 22

2 20

3 24

4 24

5 26

a) using a 3-period weighted moving average with weight 0.1 0.2 and 0.3 prepare forecasts for months 4 5 and 6 (i.e three forecasts).

b) using exponential smoothing with an alph of 0.5 prepare forecasts for months 4 5 and 6 assuming the forecast for month 3 is 24

c) which method above yield a more accurate forecast ( use MAD and MSE ) why is it more accurate ?

d) fit a simple linear regression model to the sales data and use the regression line to prepare forecast for month 6