How are trade and business related? ​

Aaron corporation, which has only one product, has provided the following data concerning its most recent month of operations: selling price $ 102 units in beginning inventory 0 units produced 4,900 units sold 4,260 units in ending inventory 640 variable costs per unit: direct materials $ 20 direct labor $ 41 variable manufacturing overhead $ 5 variable selling and administrative expense $ 4 fixed costs: fixed manufacturing overhead $ 64,200 fixed selling and administrative expense $ 2,900 the total contribution margin for the month under variable costing is: