The contribution margin income statement of Creative Donuts for May 2016 follows:

Creative sells two dozen plain donuts for every dozen custard-filled donuts. A dozen plain donuts sells for $4.00, with a variable cost of $1.60 per dozen. A dozen custard filled donuts sells for $8.00, with a variable cost of $3.20 per dozen.
Requirements
1. Calculate the weighted-average contribution margin.
2. Determine Creative's monthly breakeven point in dozens of plain donuts and custard-filled donuts. Prove your answer by preparing a summary contribution margin income statement at the breakeven level of sales. Show only two categories of costs: variable and fixed.
3. Compute Creative's margin of safety in dollars for May 2016.
4. Compute the degree of operating leverage for Creative Donuts. Estimate the new operating income if total sales increase by 40%. (Round the degree of operating leverage to four decimal places and the final answer to the nearest dollar. Assume the sales mix remains unchanged.)
5. Prove your answer to Requirement 4 by preparing a contribution margin income statement with a 40% increase in total sales. (The sales mix remains unchanged.)

CREATIVE DONUTS Contribution Margin Income Statement Month Ended May 31, 2016 Sales Revenue S 129,000 Variable Costs Cost of Goods Sold Selling Costs Administrative Costs $32,300 17,200 2,100 51,600 77,400 Contribution Margin Fixed Costs: Selling Costs Administrative Costs 21,600 7,200 28,800 S 48,600 Operating income