Please show step by step explanation.

INFO:

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 (4,400 units)		$70,400
Cost of goods sold:
Cost of goods manufactured (5,100 units)	$56,100
Inventory, April 30 (700 units)	(7,700)
Total cost of goods sold		(48,400)
Gross profit		$22,000
Selling and administrative expenses		(13,050)
Operating income		$8,950

If the fixed manufacturing costs were $15,147 and the fixed selling and administrative expenses were $6,390, prepare an income statement according to the variable costing concept. Round all final answers to whole dollars

PROBLEM:

Sales		$70,400
Variable cost of goods sold:
Variable cost of goods manufactured	??????
Inventory April 30th	???????
Total variable cost of goods sold		????????
Manufacturing margin		?????????
Variable selling and administrative expenses		?????????
Contribution margin		?????????
Fixed costs:
Fixed manufacturing costs	???????????
Fixed selling and administrative expenses	???????????
Total fixed costs		?????????
Operating income		?????????