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 $77,420. Type of Return Easy Moderate Business Sales Mix Fee Charged 504 $ 176 30$ 326 205 626 Variable cost per Return $ 98 188 238 The weighted average contribution margin is: Multiple Choice $392 O $311 $564 $158