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 1,800,000 435,000 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 11%