Jakes Roof Repair has provided the following data concerning its costs:

	Fixed Cost per Month			Cost per Repair-Hour
Wages and salaries	$	20,700		$	15.00
Parts and supplies				$	7.30
Equipment depreciation	$	2,800		$	0.35
Truck operating expenses	$	5,720		$	1.70
Rent	$	4,660
Administrative expenses	$	3,900		$	0.80

For example, wages and salaries should be $20,700 plus $15.00 per repair-hour. The company expected to work 2,900 repair-hours in May, but actually worked 2,800 repair-hours. The company expects its sales to be $51.00 per repair-hour.