Ms$.$ Reed, Director of Supply Chain and Logistics for a Calendar company, wishes to evaluate two methods of time series forecasting. She has collected quarterly calendar sales data from the years $2020$ and $2021.$ Hint: you may want to put all the data in $2$ columns to look like the example we did in class.

$20202021$

Quarter Actual Sales Quarter Actual Sales

$1140011600$

$29002900$

$33003300$

$490041100$

a$)$ Use a Na$$ve method to forecast sales for quarter $1-2022.$

$1,100$

b$)$ Use a $3-$month moving average to forecast quarter $1-2022.$

$766\mathrm{.}67$

c$)$ Use a $3-$month weighted moving average to forecast quarter $1-2022,$ use $0\mathrm{.}2,0\mathrm{.}3$ and $0\mathrm{.}5$ as the weights respectively.

$820$

d$)$ Compare the performance of the three methods by using MAD and MAPE as the performance criteria. Which method would you recommend?

e$)$ Using