engberg company installs lawn sod in home yards. the company’s most recent monthly contribution format income statement follows: amount percent of sales sales $ 145,000 100% variable expenses 58,000 40 contribution margin 87,000 60% fixed expenses 21,000 net operating income $ 66,000 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 24% increase in unit sales. 3. construct a new contribution format income statement for the company assuming a 24% increase in unit sales.