Machine-Hours Maintenance Cost January. February.. March.. April May 3,658 3,613 3,607 3,614 3,638 $52,986 $52,580 $52,504 $52,585 $52,825 S52,500 $52,943 $52,776 $52,337 June 3,604 3,653 3,634 3,588 July... August.. September.. Maintenance costs at a Tierce Corporation factory are listed above. Management believes that maintenance cost is a mixed cost that depends on machine-hours. Using the high-low method to estimate the variable and fixed components of this cost, these estimates would be closest to $14.54 per machine-hour; $52,671 per month $9.27 per machine-hour; $19,076 per month