On April 30, the end of the first month of operations, Joplin Company prepared the following income statement, based on the absorption costing concept: Joplin Company Absorption Costing Income Statement For the Month Ended April 30 Sales (6,400 units) Cost of goods sold: Cost of goods manufactured (7,300 units) Inventory, April 30 (1,000 units) Total cost of goods sold Gross profit Selling and administrative expenses Operating income $108,800 $87,600 (12,000) (75,600)$33,200(19,970)$13,230 Joplin Company Variable Costing Income Statement For the Month Ended April 30 Variable cost of goods sold: Fixed costs: $