Sales Engberg Company installs lawn sod in home yards. The company's most recent monthly contribution format income statement follows: Amount $ 130,000 Percent of Sales 100% 52,000 40% 78,000 60% 23,000 $ 55,000 Variable expenses Contribution margin Fixed expenses Net operating income Required: 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 18% increase in unit sales. 3. Construct a new contribution format income statement for the company assuming a 18% increase in unit sales