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 $ 1,200,000 320,000 880,000 640,000 $ 240,000 $ 600,000 At the beginning of this year, the company has a $150,000 investment opportunity with the following cost and revenue characteristics Sales Contribution margin ratio Fixed expenses $ 240,000 50% of sales $ 84,000 The company's minimum required rate of return is 15% Required: 1. What is last year's margin? % Margin