Chapman Pharmaceuticals, a large manufacturer of drugs, has this aggregate demand forecast $($in thousands of liters$)$ for a liquid cold medicine. $(14\mathrm{.}3)$

Month Demand

January $200$

February $120$

March $75$

April $40$

May $15$

June $7$

July $5$

August $10$

September $30$

October $70$

November $120$

December $180$

The firm has a normal production rate of $90$ thousand liters per month, and the initial inventory is $100$ thousand liters. Inventory$-$holding costs are $$30$ per $1,000$ liters per month, regular$-$time production costs are $$400$ per $1,000$ liters. Overtime costs an additional $20$ percent, and undertime costs an additional $12$ percent. Assume that there are no lost sales or rate change costs. Use the Agg Plan $$ Level and Agg Plan $$ Chase Excel templates to compute the costs of a level production rate of $90$ thousand liters per month and a chase demand production plan.