b$)$ The forecast for the next month $($Jan$)$ using the naive method $=22$ sales $($round your response to a whole number$).$

The forecast for the next period $($Jan$)$ using a $3-$month moving average approach $=21\mathrm{.}66$ sales $($round your response to two decimal places$).$

The forecast for the next period $($Jan$)$ using a $6-$month weighted average with weights of $0\mathrm{.}10,0\mathrm{.}10,0\mathrm{.}10,0\mathrm{.}20,0\mathrm{.}20,$ and $0\mathrm{.}30,$ where the heaviest weights are applied to the most recent month $=20\mathrm{.}7$ sales $($round your response to one decimal place$).$

Using exponential smoothing with $=0\mathrm{.}30$ and a September forecast of $20\mathrm{.}00,$ the forecast for the next period Jan