Phillips Company manufactures air-conditioning units for commercial buildings and has noticed considerable variation in shipping expenses from month to month as per the data below:

	Units	Total Shipping
Month	Shipped	Expense
January	4	$	2,000
February	4	$	2,900
March	5	$	2,350
April	2	$	1,260
May	3	$	2,040
June	6	$	2,700
July	8	$	3,840

8. If the air conditioners have an average sales price of $6,100, variable direct manufacturing costs are $3,050 per unit, variable manufacturing overhead costs are $1,220 per unit, and variable selling and administration costs (excluding shipping) are $240 per unit, what is the contribution margin per unit?