Swan, Inc. uses the high-low method to analyze cost behavior. The company observed that at 17,000 machine hours of activity, total maintenance costs averaged $57.10 per hour. When activity jumped to 25,000 machine hours, which was still within the relevant range, the average total cost per machine hour was $41.10.

On the basis of this information, the variable cost per machine hour for Swan was: round to nearest two decimal places