The Hawthorne Company has assembled the following data pertaining to certain costs that cannot be easily identified as either fixed or variable. Hawthorne Company has heard about a method of measuring cost functions called the high-low method and has decided to use it in this situation. Observation Month Total Operating Costs Hour's July August September October November What is the variable cost per unit? $5.25 $24.900 24.000 36.400 44,160 45,000 5,250 5,500 7,500 9.750 9,500 O $4.28 $4.67 $4.08 O