Sebastian Muffler, Inc. operates an automobile service facility. The table below shows the cost incurred during a month when 400 mufflers were replaced.

	Number of Muffler Replacements
	300		400				500
Total costs:
Fixed costs	A		$	8,400			C
Variable costs	B			5,200			D
Total costs	E		$	13,600			F
Cost per muffler replacement:
Fixed cost	G			H			I
Variable cost	J			K			L
Total cost per muffler replacement	M			N			O