The contribution margin income statement of Delectable Donuts for August 2012 follows:
DELECTABLE DONUTS Contribution Margin Income Statement For the Month of August 2012
Sales revenue		$150,000
Variable costs:
Cost of goods sold	$41,000
Marketing costs	15,000
General and administrative costs	4,000	60,000
Contribution margin		$90,000
Fixed costs:
Marketing costs	37,800
General and administrative costs	12,600	50,400
Operating income		$39,600
Delectable sells four dozen plain donuts for every dozen custard-filled donuts. A dozen plain donuts sells for $4, with total variable cost of $1.60 per dozen. A dozen custard-filled donuts sells for $5, with total variable cost of $2 per dozen.
Requirements:
1. Calcuate the weighted-average contribution margin.
2. Determine Delectable's monthly breakeven point in dozens of plain donuts and custard-filled donuts. Prove your answer by preparing a summary contribution.