ACME estimates that it costs $1.50 per month for each unit of this appliance carried in inventory (estimated by the beginning and ending inventory levels each month). Currently ACME has 120 units in inventory on hand. To maintain a level of workforce, the company wants to produce at least 400 units per month, it also wants to maintain a safety stock of at least 50 units per month. ACME wants to determine how many to manufacture during each of the next 4 months to meet the expected demand at the lowest cost.