$3$a$)$ Forecast week $4$ and $5$ using $3$ weeks moving averages with weights $0\mathrm{.}5,0\mathrm{.}3,0\mathrm{.}2$

Full workings must be shown!$3A$

Forecast week $4$ and $5$ using $3$ weeks moving averages with weights $0\mathrm{.}5,0\mathrm{.}3,0\mathrm{.}2$

Full workings must be shown!