15 Portia Company is a retailer of hammers. Portia pays $4.55 for each hammer and sells them for $9.00. Monthly fixed costs are $31150 The hammer cost is the only variable cost a. What is the contribution margin per unit? (Round your answer to 2 decimal places.) Coeullen Man perunt b. What is the break-even point in units? (Do not round intermediate calculations.) units c. How many units will Portia need to sell to eam target profit of $29.370? (Do not round intermediate calculations.) al Pumber of Unite Chick my work