Engberg Company installs lawn sod in home yards. The company's most recent monthly contribution format income statement follows: Sales Variable expenses Contribution margin Fixed expenses Net operating income Required: Percent of Amount Sales $ 138,000 100x 55,200 40% 82,800 60% 21,000 $ 61,800 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 25% increase in unit sales 3. Construct a new contribution format income statement for the company assuming a 25% increase in unit sales