Baker Company has a product that for $30 per unit. The variable expenses are $20 per unit, and fixed expenses total $40,000 per year. Required: a.) What is the total contribution margin at the breakeven point? b.) What is the contribution margin ratio for the product? c.) If total sales increase by $20,000 and fixed expenses remain unchanged, by how much would net operating income be expected to increase? d.) The marketing manager wants to increase advertising by $8,000 per year. How many additional units would have to be sold to increase overall net operating income by $3,000