Using the data set below, what would be the forecast for period $4$ using a three period moving average: $($Choose the closest answer.$)$ Period wN Actual Demand $10,00012,40013,25015,75020,50018,500$ O a$.12,244$ O b$.11,500$ O c$.11,883$ O d$.14,008$ Using the data set below, what would be the forecast for period $5$ using a four period weighted moving average? The weights for each period are $0\mathrm{.}05,0\mathrm{.}15,0-30,$ and $0\mathrm{.}50$ from the oldest period to the most recent period, respectively. $($Choose the closest answer.$)$ Period Actual Demand $10,00012,40013,25014,75015,22018,500$ O O O O a$.13,105$ b$.13,710$ c$.14,610$ d$.12,820$