Figure 3-5. Maxwell Company makes treadmills. The company controller wants to calculate the fixed and variable costs associated with the janitorial costs incurred in the factory. Data for the past four months were collected. Janitorial Machine Month costs hours September $11,000 575 October 11,400 610 November 10,200 510 December 10,725 550 Refer to Figure 3-5.

Using the high-low method calculate the fixed cost of the janitorial services

a. $4,080 b. $7,320 c. $6,120 d. none of these are correct