Nova Company's total overhead cost at various levels of activity are presented below: Month April May June July Machine- Hours 46,000 36,000 56,000 66,000 Total Overhead Cost $ 190,880 $ 167,080 $ 214,680 $ 238,480 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 $ 46,800 64,000 56,280 $167,080 Nova Company's management wants to break down the maintenance cost into its variable and fixed cost elements. Required: 1. Estimate how much of the $238,480 of overhead cost in July was maintenance cost. (Hint: to do this, it may be helpful to first determine how much of the $238,480 consisted of utilities and supervisory salaries. Think about the behavior of variable and fixed costs.) 2. Using the high-low method, estimate a cost formula for maintenance in the form Y = a +bX. 3. Express the company's total overhead cost in the form Y = a +bX. 4. What total overhead cost would you expect to be incurred at an activity level of 41,000 machine-hours