The Lawn Plus Fertilizer Company distributes fertilizer to various lawn and garden shops. The company must base its quarterly production schedule on a forecast of how many tons of fertilizer will be demanded $($in tons$)$ from it$.$ The company has gathered the following data for the past three years from its sales records.

Year

$1$

$2$

$3$

Quarter

$1$

$2$

$3$

$4$

$1$

$2$

$3$

$4$

$1$

$2$

$3$

$4$

Demand

$105$

$150$

$93$

$121$

$140$

$170$

$105$

$150$

$150$

$170$

$110$

$130$

Q$)$ The following is a plot of the demand. Base on the plot, apply the most suitable method to forecast demand for each quarter in year $4.$ Use a $3-$year moving average to forecast the demand for year $4.$