Given the following data, what is MAPE for the weighted moving average forecast with weights of $\mathrm{.}5,\mathrm{.}3,\mathrm{.}2,$ respectively WMA $($:${?}_{\mathrm{.}5,\mathrm{.}3,\mathrm{.}2}\}?$

Month Demand

$1,19$

$2,20$

$3,18$

$4,19$

$5,17$