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.$

Type of Return

Sales Mix

Fee Charged

Variable Cost per Return

Easy

$50\%$

$ $50$

$ $30$

Moderate

$30\%$

$125$

$75$

Business

$20\%$

$275$

$100$

Determine the weighted$-$average contribution margin

Determine the break$-$even points in units using the weighted average contribution margin

Determine the number of units of each product that will be sold at the break$-$even point