Analyzing Income under Absorption and Variable Costing Variable manufacturing costs are $87 per unit, and fixed manufacturing costs are $61,200. Sales are estimated to be 4,500 units. If an amount is zero, enter " 0. Round intermediate calculations to the nearest cent and your final answers to the nearest dollar. a. How much would absorption costing operating income differ between a plan to produce 4,500 units and a plan to produce 6,800 units? b. How much would variable costing operating income differ between the two production plans