Stratford Company distributes a lightweight lawn chair that sells for $30 per unit. Variable expenses are 40% of sales, and fixed expenses total $526,500 annually. 4. Assume that the operating results for last year were as follows: Sales Less: Variable expenses Contribution margin Less: Fixed expenses Net operating income $1,170,000 468,000 702,000 526,500 $ 175,500 a. Compute the degree of operating leverage at the current level of sales. (Round your answer to 1 decimal place.) Degree of operating leverage b. The president expects sales to increase by 30% next year. By how much should net operating income increase? Increase in operating income