Nova Company's total overhead cost at various levels of activity are presented below: Month April May June July Machine- Hours 55,000 45,000 65,000 75,000 Total Overhead Cost $ 192,300 $ 169,300 $ 215,300 $ 238,300 Assume that the total overhead cost above consists of utilities, supervisory salaries, and maintenance. The breakdown of these costs at the 45,000 machine-hour level of activity is: Utilities (variable) Supervisory salaries (fixed) Maintenance (mixed) Total overhead cost $ 49,500 52,000 67,800 $169,300 Nova Company's management wants to break down the maintenance cost into its variable and fixed cost elements. olpful to first 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 $238,300 of overhead cost in July was maintenance cost. (Hint to do this, it may be helpful to first determine how much of the $238.300 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 50,000 machine-hours