Raven Incorporated sells a single product for $54. Variable costs include $31.04 for each unit plus a $10 selling expense per unit. Fixed costs are $236,880 per month. Required: a. What is the contribution margin ratio? b. What is the break-even sales revenue? c. What sales revenue is needed to achieve a $216,480 per month profit? Complete this question by entering your answers in the tabs below. What is the contribution margin ratio? Note: For all the requirements, do not round intermediate calculations