Deforrest Marine Motors manufactures engines for the speedboat racing circuit. As part of their annual planning cycle, they forecasted demand for the next four quarters. The number of available days of production and the anticipated demand are given below. Q1 Q2 Q3 Q4 Days of Production 65 68 61 64 Demand 1,800 2,200 1,700 2,400 They also estimated many of the costs required to conduct operations planning. Some of these key figures are listed below. Employees 30 Hire Cost $1,200/employee Production Rate 1 unit/employee/day Fire Cost $800/employee Production Cost $1,000/unit Subcontracting Cost $1,800/unit Backorder Cost $200 Subcontracting Limit 400 units maximum Overtime Cost $1,500 Inventory Cost $100/unit/quarter Overtime Limit <= 25% of Reg. Production Initial Inventory 280 units Assumptions: Deforrest Marine Motors will maintain the same number of employees (30 employees) for the entire year. Holding costs for each quarter are calculated on the average inventory level and in U.S. dollars. Given that the beginning inventory (start of Q1) was 280 units, what would be the average on-hand inventory for the first quarter