How do i calculate percent of sales

Engberg Company installs lawn sod in home yards. The company's most recent monthly contribution format income statement follows: 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 8% increase in unit sales. 3. Construct a new contribution format income statement for the company assuming a 8% increase in unit sales. Complete this question by entering your answers in the tabs below. Construct a new contribution format income statement for the company assuming a 8% increase in unit sales