Engberg Company installs lawn sod in home yards. The company's most recent monthly contribution format income statement follows: Percent of Sales 100% 408 603 Amount $ 135,000 54,000 81,000 15,000 $ 66,000 Sales 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 16% increase in sales. 3. Construct a new contribution format income statement for the company assuming a 16% increase in sales