Westerville Company reported the following results from last years operations: Sales $ 1,500,000 Variable expenses 650,000 Contribution margin 850,000 Fixed expenses 580,000 Net operating income $ 270,000 Average operating assets $ 1,000,000 At the beginning of this year, the company has a $160,000 investment opportunity with the following cost and revenue characteristics: Sales $ 240,000 Contribution margin ratio 70 % of sales Fixed expenses $ 144,000 The companys minimum required rate