Sales volume (units). Cost of sales Selling and administrative costs..... 4.000 5,000 $338,000 $422.500 $89,600 $106,000 Use the information to answer Question 8-10. Callaham 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 $115.80 per unit. The best estimate of the total monthly fixed cost is: sk (15) $24,000 $478,050 $427,600 O $427,600