At Ready Corporation, maintenance is a variable overhead cost that is based on machine hours. The performance report for showed that actum maintenance costs totaled $10.580 and that the associated rate variance was $320 unfavorable it 5300 machine hours were chany woned during July, the standard maintenance cost per machine hour was: Multiple Choice $186 per MH $191 per MH $1.80 per MH $1.97 per MH