b a $2$year moving average is used to make the forecast, the MAD based on this $100$ miles $($round your response to one decimal place$)$ The forecast for year $6$ using a weighted $2$year moving average with weights of $0\mathrm{.}45$ and $0\mathrm{.}55($the weight of $0\mathrm{.}55$ is for the most recent pen nearest whole number $)$