how to calculte the fixed cost?

Company ABC has recorded sales revenue of RM12,775.00 in the previous month for 3,650 units sold. The total costs incurred for the production is RM10617.50 with RM1.95 is the variable cost per unit. Recently, Company ABC received a special order from their customer with a one-time order for 1,500 units at a discount of 10% from the current price. Please suggest to the Company ABC whether or not they accept this special order by using differential analysis. Selling Price per unit = 12775/3650= 3.5 If the company decides no to accept the order, total revenue would be for 3650 units whereeas if the special order is accepted revenue would be for 5150 units Selling price for special order =3.5-10% = 3.15 Accordingly, the differential analysis has been presented as under (Figures in RMI) Alternative Difference Status Quo 3650 1500 5150 Sales Revenue 12,775 12,775 4,725 17,500 4,725 Variable Cost at 1.95 p.u 7,118 7,118 2,925 10,043 2,925 Contribution Margin 5,658 5,658 1,800 7,458 1,800 Fixed Cost 4,960 4,960 1,425 6,385 1,425 Operating Profit 698 698 375 1,073 375 ABC gets an incremental contribution of RMI1800 and an additional operating profit of 375. Therefore the company should accept the order