Nova Company's total overhead cost at various levels of activity are presented below. Month April May June July Machine Hours 45,000 35,000 55,000 65,000 Total Overhead Cost $ 182,800 $ 158,800 $. 206,800 $ 230,800 Assume that the total overhead cost obove consists of utilities, supervisory salaries, and maintenance. The breakdown of these costs at the 35.000 machine-hour level of activity is Utilities (variable) Supervisory salaries (fixed) Maintenance (mixed) Total overhead cost $ 45,500 61,000 52,300 $158,800 Nove Company's management wants to break down the maintenance cost into its variable and fixed cost elements Required: 1. Estimate how much of the $230,800 of overhead cost in July was maintenance cost (Hint to do this, it may be helpful to first determine how much of the $230,800 consisted of utilities and supervisory solaries. 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-abx 3 Express the company's total overhead cost in the form yax 4. What total overhead cost would you expect to be incurred at an activity level of 40.000 machine hours