Required Information. The Foundational 15 (Algo) [LO10-1, LO10-2] [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 $ 2,300,000 670,000 1,630,000 1,170,000 Net operating income $460,000 Average operating assets $1,437,500 At the beginning of this year, the company has a $287,500 investment opportunity with the following cost and revenue characteristics: Contribution margin ratio Sales Fixed expenses $460,000 50 % of sales $161,000 The company's minimum required rate of return is 15% Foundational 10-1 (Algo) 13 Required: 1. What is last year's margin? Margin %