iacob corporation is a wholesaler that sells a single product. management has provided the following cost data for two levels of monthly sales volume. the company sells the product for $176.00 per unit. sales volume (units) 8,400 10,040 cost of sales $ 705,600 $ 843,360 selling and administrative costs $ 718,000 $ 752,440 the best estimate of the total contribution margin when 9,200 units are sold is: