W&W Tax Service offers tax and consulting services to individuals and small businesses. Data for fees and costs for three types of tax returns is presented in the table below. Fixed costs total $67,500. Type of Return Easy Sales Mix 50% 30% 20% Fee Charged $ 160 310 610 Variable Cost per Return $ 90 180 230 Moderate Business The weighted-average contribution margin is: Multiple Choice 3. 540 4. 150 5. 1080 O $360 $295 O