Analyzing Income under Absorption and Variable Costing Variable manufacturing costs are $91 per unit, and fixed manufacturing costs are $88,800. Sales are estimated to be 6,000 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 6,000 units and a plan to produce 7,400 units? $ b. How much would variable costing operating income differ between the two production plans