Menlo company distributes a single product. the company’s sales and expenses for last month follow: total per unit sales $ 450,000 $ 30 variable expenses 180,000 12 contribution margin 270,000 $ 18 fixed expenses 216,000 net operating income $ 54,000 required: 1. what is the monthly break-even point in unit sales and in dollar sales? 2. without resorting to computations, what is the total contribution margin at the break-even point?