4. Assume that the operating results for last year were: Sales Variable expenses $ 2,080,000 1,040,000 Contribution margin Fixed expenses 1,040,000 180,000 Net operating income $ 860,000 a. Compute the degree of operating leverage at the current level of sales. (Round your answer to 2 decimal places.) gree of operating b. The president expects sales to increase by 11% next year. By what percentage should net operating income increase? (Round intermediate calculations to 2 decimal places and final answer to the nearest percentage.) operating income increases by Type here to search F1 F2 F3 F4 F5 F6FF8F 8 2 3 4 5 6