acob 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 $103.40 per unit. Sales volume (units) Cost of sales Selling and administrative costs 5,000 6,000 $315,500$ 378,600 $ 162,500$ 177,600 The best estimate of the total contribution margin when 5,300 units are sold is: $56,710 $133,560 $41,340 $213,590