Crosshill Company's total overhead costs at various levels of activity are presented below: Month April May June July Total Overhead Cost Machine-Hours 70,000 $202, 600 60,000 $ 180, 900 80,000 $ 224, 300 90,000 $ 246,000 Assume that the overhead cost above consists of utilities, supervisory salaries, and maintenance. The breakdown of these costs at the 60,000-machine-hour level of activity in May is as follows: Utilities (variable) Supervisory salaries (fixed) Maintenance (mixed) Total overhead cost $ 50, 400 21.000 109, 500 $ 180,900 The company wants to break down the maintenance cost into its variable and fixed cost elements.