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 (2,500 units) Cost of goods sold: Cost of goods manufactured (2,900 units) $63,800 Inventory, April 30 (400 units) (8,800) Total cost of goods sold Gross profit $22,500(55,000) Selling and administrative expenses Operating income $9,620 Joplin Company Variable Costing Income Statement For the Month Ended April 30 Variable cost of goods sold: Fixed costs