Nova Companys total overhead cost at various levels of activity are presented below: Month Machine- Hours Total Overhead Cost April 50,000 $ 202,100 May 40,000 $ 174,700 June 60,000 $ 229,500 July 70,000 $ 256,900 Assume that the total overhead cost above consists of utilities, supervisory salaries, and maintenance. The breakdown of these costs at the 40,000 machine-hour level of activity is: Utilities (variable) $ 60,000 Supervisory salaries (fixed) 52,000 Maintenance (mixed) 62,700 Total overhead cost $ 174,700 Nova Companys management wants to break down the maintenance cost into its variable and fixed cost elements. Required: 1. Estimate how much of the $256,900 of overhead cost in July was maintenance cost. (Hint: to do this, it may be helpful to first determine how much of the $256,900 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 companys 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 45,000 machine-hours?