Tirri Corporation has provided the following information:

	Cost per Unit	Cost per Period
Direct materials	$ 7.15
Direct labor	$ 4.40
Variable manufacturing overhead	$ 1.20
Fixed manufacturing overhead		$ 23,700
Sales commissions	$ 1.25
Variable administrative expense	$ 0.50
Fixed selling and administrative expense		$ 8,100

If the selling price is $27.40 per unit, the contribution margin per unit sold is closest to: