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 $ 1,000,000 300,000 700,000 500,000 200,000 $ 625,000 $ At the beginning of this year, the company has a $120,000 investment opportunity with the following cost and revenue characteristics: Sales Contribution margin ratio Fixed expenses $ 200,000 60% of sales $ 90,000 The company's minimum required rate of return is 15%. Required: 1. What is last year's margin? 1.61%