$\backslash$table$[[1,$Month,Demand for Samsung M$11],[2,$January,$420],[3,$February,$340],[4,$March,$520],[5,$April,$600],[6,$May,$450],[7,$June,$550],[8,$July,$700],[9,$August,$780],[10,$September,$800],[11,$October,$840],[12,$November,$910],[13,$December,$880]]$

a$)$ Calculate the $3-$monthly moving average from January to December.

Calculate the $4-$monthly moving average from January to December

Calculate the $3-$month weighted moving average for all the months if the weightings are given as

Month Weights

Month $1($two months before the current month$)0\mathrm{.}2$

Month $2($one month before the current month$)0\mathrm{.}3$

Month $3($Most current month$)0\mathrm{.}5$Calculate the $4-$month weighted moving average for all the months if the weightings are given as

Month Weights

Month $1($three months before the current month$)0\mathrm{.}15$

Month $2($two months before the current month$)0\mathrm{.}25$

Month $3($one month before the current month$)0\mathrm{.}3$

Month $4($Most current month$)0\mathrm{.}3$

$[4$ Marks$]$

e$)$ Explain what happens when you increase the number of periods in a moving average forecast. $[1\mathrm{.}5$ Mark$]$