Required information [The following information applies to the questions displayed below.] Westerville Company reported the following results from last year's operations: Sales Variable expenses Contribution margin Fixed expenses Net operating income Average operating assets $ 1,300,000 440,000 860,000 600,000 $ 260,000 $ 812,500 At the beginning of this year, the company has a $162,500 investment opportunity with the following cost and revenue characteristics: Sales $ 260,000 Contribution margin ratio Fixed expenses 80% of sales $ 182,000 The company's minimum required rate of return is 15%. Required: 1. What is last year's margin? Margin %