Shown here is an income statement in the traditional format for a firm with a sales volume of 16,500 units:

Revenues	$	132,000
Cost of goods sold ($11,000 + $3.00/unit)		60,500
Gross profit	$	71,500
Operating expenses:
Selling ($2,400 + $0.95/unit)		18,075
Administration ($4,700 + $0.40/unit)		11,300
Operating income	$	42,125

b. Calculate the contribution margin per unit and the contribution margin ratio.