Fanning Computer Services, Inc. has been in business for six months. The following are basic operating data for that period: 3333333 Service hours Revenue Operating costs July 114 $6,726 $ 4,240 Aug. 136 $ 8,024 $5,260 Month Sept. Oct. 258 428 $15, 222 $25, 252 $ 7,150 $11,140 Nov. 314 $18,526 $ 9,170 Dec. 326 $19,234 $10,560 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