What is the average amount purchased per customers in a five day period number of customers 12,15,13,18,21 and the amount purchased is $150,$175,$120,$215,$250

Raymond just got done jumping at super bounce trampoline center. the total cost of his session was $43.25 . he had to pay a $7 entrance fee and $1.25 for every minute he was on the trampoline. write an equation to determine the number of minutes (t) that raymond was on the trampoline.