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 $ 229,150 $ 201,650 $ 256,650 $ 284,150 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 cont $ 72,000 62,000 67,650 $ 201,650 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 $284,150 of overhead cost in July was maintenance cost. (Hint: to do this, it may be helpful to first determine how much of the $284,150 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