Given the following demand data, $(32)$ Data $123456789101112131415$ Period a$.$ Compute a weighted average forecast using a weight of $\mathrm{.}40$ for the most recent period, $\mathrm{.}30$ for the next most recent, $\mathrm{.}20$ for the next, and $\mathrm{.}10$ for the next. b$.$ If the actual demand for period $6$ is $39,$ forecast demand for period $7$ using the same weights as in part a$.$ Period Demand $142240343440541$ MA$3$ MA$5$ Demand