Nova Company's total overhead cost at various levels of activity are presented below: Month April Total Overhead Cost $164,880 $ 142,080 $ 187,680 $ 210,480 Machine- Hours 46.000 36,000 56.000 66,000 May June July Assume that the total overhead cost above consists of utilities, supervisory salaries, and maintenance. The breakdown of these costs at the 36,000 machine-hour level of activity is: Utilities (variable) Supervisory salaries (fixed) Maintenance (mixed) Total overhead cost $ 43,200 45,000 53,880 $142.000 Nova Company's management wants to break down the maintenance cost into its variable and fixed cost elements Required 1 Required 2 Required 3 Required 4 Using the high-low method, estimate a cost formula for maintenance in the form Y = a + bx. (Do not round your interme calculations. Round the "Variable cost per unit" to 2 decimal places.) Y = 60,000 - $2.28