The controller of Jeong Company prepared the following projected income statement:

Sales............................................... $92,000
Total variable cost.......................... 26,680
Contribution margin.................... $65,320
Total fixed cost............................... 42,600
Operating income........................ $22,720

Required:
1. Calculate the contribution margin ratio.
2. Calculate the variable cost ratio.

3. Calculate the break-even sales revenue for Jeong.
4. How could Jeong increase projected operating income without increasing the total sales revenue?