The following table contains the number of complaints received in a department store for the first six months of operation.

$\backslash$table$[[$Month$,$Complaints$],[$January$,36],[$February$,45],[$March$,81],[$April$,90],[$May$,108],[$June$,144]]$

a$.$ Use three$-$month moving average and three$-$month weighted moving average $($weight the most recent month $05,$ the second recent month $0\mathrm{.}25$ and the third $0\mathrm{.}25)$ to develop forecast.

b$.$ Calculate MAD for both methods and conclude which one is better and why.