The following information is available for a company's utility cost for operating its machines over the last four months.

Month	Machine hours	Utility cost
January	900	$5,450
February	1,800	$6,900
March	2,400	$8,100
April	600	$3,600

Using the high-low method, the estimated total fixed cost for utilities is:

$1,500$3,600$6,000$3,300$2,100