Question $2($Cont$\text{'}$d$)$

Requirements:

a$)$ Plot a line chart showing the following THREE $(3)$ lines:

$($i$)$ Actual demand line;

$($ii$)$ Na$$ve approach forecast line;

$($iii$)3-$periods moving average line.

$[$Suggestion: Use MS Excel to plot the THREE $(3)$ lines. Copy and paste the chart onto the MS Word report.$]$

$(10$ marks$)$

b$)$ Compute the Mean Squared Errors $($MSE$)$ for the Na$$ve approach and $3-$periods moving average method for periods $4$ to $20.$ Tabulate your answers with ONE $(1)$ decimal place.

$(10$ marks$)$

c$)$ Comment on the MSE results obtained in part $($b$).$ Use the more accurate method to forecast the demand for period $21.$

$(5$ marks$)$