a$)$Compute a three$-$quarter moving average forecast for quarters $4$ through $13$ and compute the forecast error for each quarter. b$)$Compute a five$-$quarter moving average forecast for quarters $6$ through $13$ and compute the forecast error for each quarter. c$)$Compute a weighted three$-$quarter moving average forecast using weights of $0\mathrm{.}50,0\mathrm{.}33,$ and $0\mathrm{.}17$ for the most recent, next recent, and most distant data, respectively, and compute the forecast error for each quarter. $(2$ marks$)$d$)$Compare the forecasts developed in parts $($a$),($b$),$ and $($c$)$ using cumulative error. Which forecast appears to be most accurate? Do any exhibit any bias? $(1$ mark$)$