Below are the aggregate demand requirements and other data for the upcoming four quarters.

Quarter

Demand

Previous quarter's output

$1550$ units

$1$

$1200$

Beginning inventory

$150$ units

$2$

$1400$

Stockout cost

$$50$ per unit

$3$

$1650$

Inventory holding cost

$$10$ per unit at end of quarter

$4$

$1300$

Hiring workers

$$8$ per unit

Laying off workers

$$12$ per unit

Unit cost

$$40$ per unit

Overtime

$$15$ extra per unit