When the calculations for the requirements below are correct, the cells will change to yellow. R&R Tax Service offers tax and consulting services to individuals and small businesses. Data for fees and costs for three types of tax returns follow. Fixed costs total $18,000. Variable Cost per Type of Return Sales Mix Fee Charged Return Easy 50% $50 $30 Moderate 30% 125 75 Business 20% 275 100 Required: (1) Determine the weighted-average contribution margin. (2) Determine the break-even point in units using the weighted-average contribution margin. (3) Determine the number of units of each product that will be sold at the break-even point. Sales mix Contribution margin per Total per unit Easy Moderate Business Weighted-average contribution margin Break-Even Units returns Easy Moderate Business Total Numbe of units Sales mix to break even Units sales at break-even point returns returns returns returns