Nova Company's total overhead cost at various levels of activity are presented below: Total Overhead Cost Machine Month April May Hours 55,0 %222,800 45,000 194,800 65,000$250,8e0 75,000 278,800 une July 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 $ 72,000 54,800 68,800 $194,800 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 $278,800 of overhead cost in July was maintenance cost. (Hint:to do this, it may be helpful to first determine how much of the $278,800 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 tbX. 4. What total overhead cost would you expect to be incurred at an activity level of 50,000 machine-hours