2. Given the projected demands for the next six months as shown in Table 1, prepare an aggregate plan that uses inventory, regular time and overtime, and backorders. Regular time is 150 units per month. Overtime is a maximum of 20 units per month. Overtime cost is RM30 per unit, backorder cost is RM20 per unit, inventory holding cost is RM5 per unit, regular time cost of RM20 per unit, and beginning inventory is zero. Table 1: Forecast for 6 months Month 1 2 3 4 5 6 Forecast 180 170 140 150 130 150 (20 marks)