Duncan had revenues of $400,000 in March. Fixed costs in March were $104,000, and profit was $96,000. Answer the following questions: Required: a. What was the contribution margin ratio? b. What monthly sales volume (in dollars) would be needed to break even? c. What was the margin of safety in dollars for March? Complete this question by entering your answers in the tabs below: What was the contribution margin ratio? What monthly sales volume (in dollars) would be needed to break even? Note: Do not round intermediate calculations. Round final answers to the nearest whole dollars. What was the margin of safety in dollars for March? Note: Do not round intermediate calculations. Round final answers to the nearest whole dollars