Determine forecast for period $8$ using:

$2-$period moving average

$4-$period moving average

$2-$period weighted moving average with

t$-1$ weighted $0\mathrm{.}6$ and t$-2$ weighted $0\mathrm{.}4$

$$ Exponential smoothing with alpha$=0\mathrm{.}2$

and the period $1$ forecast being $310$