Why is the answer 47,300? Please show work and explain

a Aggregate demand for a product family is given in the table below for the 4 quarters of 2007. Production cost on regular time is $20 per unit. Production cost on overtime is $23 per unit. Subcontracting cost is $25 per unit. The inventory cost is $1 per unit per quarter. The backorder cost is $2 per unit per quarter. Demands and capacities for the four quarters are given in the table below. Determine an optimal aggregate plan and report the optimal total cost of meeting demand for 2007. Q3 Capacity Q1 Q2 Q4 Reg Q1 ? ? ? ? 500 Ovt Q1 ? ? ? ? 200 Sub Q1 ? ? ? ? ? 300 Reg Q2 ? 2 ? ? ? 500 Ovt Q2 ? ? ? ? 200 Sub Q2 ? ? ? ? 300 Reg Q3 ? ? ? ? 500 Ovt Q3 ? ? ? ? 200 Sub Q3 ? ? 2 2 ? ? ? 300 Reg 24 ? ? ? ? ? 500 Ovt 24 ? ? ? ? 200 Sub Q4 ? ? ? ? 300 Demand 400 900 600 400 Ovt Q1 ? ? ? ? 200 Sub Q1 ? ? ? ? 300 Reg Q2 ? ? ? ? ? 500 Ovt Q2 ? ? ? ? 200 Sub Q2 ? ? ? ? 300 Reg Q3 ? ? ? ? 500 Ovt Q3 ? ? ? ? 200 Sub Q3 ? ? ? ? 300 Reg Q4 ? ? ? ? 500 Ovt Q4 ? ? ? ? 200 Sub Q4 ? ? ? ? 300 Demand 400 900 600 400 Answer: 48050 X The correct answer is: 47300 Incorrect Marks for this submission: 0.00/1.00