.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 variable cost per machine hour for utilities is:

$3.38

$6.00

$6.17

$4.22

$2.50