He thinks that two methods could be used to forecast future sales: linear regression and weighted moving average.

$3\mathrm{.}1$ Using Excel, please run linear regression on this data. Based on the results you obtain; do you think that

linear regression is appropriate in this case? Why?

$3\mathrm{.}2$ Which forecasting method do you think is best suited to forecast this data? Why? Apply the suggested

forecasting method.