Thornton Computer Services, Inc. has been in business for six months. The following are basic operating data for that period: Dec. Month Service hours July 120 Revenue Operating costs $6,000 $4,300 Aug. 136 $6,800 $5,300 Sept. Oct. 260 $13,000 $ 7,100 420 $21,000 $11,200 Nov. 320 330 $16,000 $16,500 $9,100 $10,600 Required a. What is the average service revenue per hour in each month and the overall average for the six-month period? b. Use the high-low method to estimate the total monthly fixed cost and the variable cost per hour. c. Determine the average contribution margin per hour. Complete this question by entering your answers in the tabs below. Required A Required B Required C What is the average service revenue per hour in each month and the overall average for the six-month