Engberg Company installs lawn sod in home yards. The company's most recent monthly contribution format income statement follows: Percent of Sales Variable expenses Contribution margin Fixed expenses Net operating income. Required: Amount Sales $ 84,000 100% 33,600 50,400 40 60% 38,640 $ 11,760 1. What is the company's degree of operating leverage? 2. Using the degree of operating leverage, estimate the impact on net operating income of a 6% increase in unit sales. 3. Construct a new contribution format income statement for the company assuming a 6% increase in unit sales.