Example $2-$ Weighted

$($a$)$ Give a forecast for the mileage of the $6^{th}$ year using a $2-$year weighted moving average with a weight of $0\mathrm{.}6$ for the most recent period, and $0\mathrm{.}4$ for the previous period.

$($b$)$ Give a forecast for the mileage of the $6^{th}$ year using a $5$ year weighted moving average where half the weight is given to the most recent year, and the remaining weight is distributed evenly among the $4$ years previous to that.