! 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 $1,600,000 700.000 900,000 660,000 $ 240,000 $1,000,000 At the beginning of this year, the company has a $325,000 investment opportunity with the following cost and revenue characteristics: Sales Contribution margin ratio Fixed expensen $ 520,000 70 of sales $ 312,000 The company's minimum required rate of return is 15% Required: 1. What is last year's margin? Margin %