2 . 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. Month Machine Hours Total Cost July 555 $158 , 421 August 444 127, 889 September 222 48, 292 October 111 31, 881 November 124 34 , 329 December 497 140 , 979 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) (6 points) and (b) find and prove the fixed costs show your work. (4 points)