The acc tutoring service provides tutoring to accounting students. the volume of tutoring is low at the beginning of the semester and increases before exams. acc had its highest level of service in may when they provided 4,300 hours of tutoring at a total cost of $125,000 and its lowest level of service in january when they provided 1,500 hours of tutoring at a total cost of $55,000. using the high-low method, the estimated variable cost per hour is