Engberg Company installs lawn sod in home yards. The company's most recent monthly contribution format income statement follows: Percent of Sales 100% 40% Amount Sales $139,000 Variable expenses 55,600 Contribution margin 83,400 Fixed expenses 20,000 Net operating income $ 63,400 60% 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 11% increase in sales. 3. Construct a new contribution format income statement for the company assuming a 11% increase in sales