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 Amount $ 146,000 Percent of Sales 58,400 100% 40 87,600 60% 21,000 $ 66,600 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 17% increase in unit sales. 3. Construct a new contribution format income statement for the company assuming a 17% increase in unit sales.