Gates Cleaning Co. leases a vacuum cleaning system for a basic monthly fee plus an additional cost per hour used above a given minimum for each month. Given below is the information for the most recent six-month period on the number of machine hours of use and the total cost under this lease. You are to provide information for planning on the variable and fixed cost elements in this contract. Use the high-low method to (a) determine the variable cost per machine hour (please show your work, take answer out 2 decimal places) ( 6 points) and (b) find and prove the fixed costs show your work. (4 points)