Please solve steps a$,$b$,$c$,$d

Land Pride is evaluating its production needs for a large machine tool that wears down every few months. The operations manager, using hisforical demand data, wants to predict the demand for the next several years to adjust production strategies effectively. The data provided reflects the actual demand observed over the past $11$ years.

The following table shows the actual demand observed over the last $11$ years:

$\backslash$table$[[$Year$,1,2,3,4,5,6,7,8,9,10,11],[$Demand$,8,9,4,9,12,7,13,12,9,9,7]]$

This exercise contains only parts $b,c,$ and $d.$

b$)$ Using the $3-$year moving average, provide the forecast from periods $4$ through $12($round your responses to one decimal place$).$

$\backslash$table$[[$Year$,4,5,6,7,8,9,10,11,12],[$Forecast$,,,,,,,,,$