Westerville Company reported the following results from last year's operations: Sales Variable expenses Contribution margin Fixed expenses Net operating income. Average operating assets $ 1,800,000 435,000 1,365,000 1,005,000 $360,000 $ 1,200,000 At the beginning of this year, the company has a $300,000 investment opportunity with the following cost and revenue characteristics: Sales Contribution margin ratio Fixed expenses $360,000 70 % of sales $216,000 The company's minimum required rate of return is 10% Required: 1. What is last year's margin? Margin %