Answer is 239.4 need Explanation how can we get this answer .

Question 4 Ollpts A company's forecast of demand in shown in the following table. Regular production costs $118 per unit with a monthly capacity of 53 units. Subcontracting costs $256 per unit and has unlimited capacity. It costs $13.3 per unit per month to hold inventory and $38 per unit per month to run backlogs. Penod Forecast 1 70 2 72 3 88 Correct Answer I} 239.4 margin of error +,/ 0.001 What is the total cost of holding inventory using a LEVEL aggregate plan