For the stable demand item in the Table, forecast at week $10$ using

$1)$ Na$$ve method

Week Actual

demand

$1120$

$2100$

$3116$

$498$

$5118$

$6125$

$7110$

$8121$

$9114$

$10?$

$4)$ Exponential smoothing using $=0\mathrm{.}7$ assuming the forecast at Week $9$ was $120$

$3)$ Three period weighted moving average using weights of

$0\mathrm{.}6,0\mathrm{.}3,$ and $0\mathrm{.}1$ in the descending order of recent periods

$2)$ Four period moving average