Engberg Company installs lawn sod in home yards. The companys most recent monthly contribution format income statement follows: Amount Percent of Sales Sales $ 139,000 100 % Variable expenses 55,600 40 % Contribution margin 83,400 60 % Fixed expenses 15,000 Net operating income $ 68,400 Required: 1. What is the companys degree of operating leverage? 2. Using the degree of operating leverage, estimate the impact on net operating income of a 17% increase in sales. 3. Construct a new contribution format income statement for the company assuming a 17% increase in sales.