Nova Company's total overhead cost at various levels of activity are presented below: Month April May June July Machine- Hours 52,000 42,000 62,000 72,000 Total Overhead Cost $ 218,900 $ 193,400 $ 244,400 $ 269,900 Assume that the total overhead cost above consists of utilities, supervisory salaries, and maintenance. The breakdown of these costs at the 42,000 machine-hour level of activity is: Utilities (variable) Supervisory salaries (fixed) Maintenance (mixed) Total overhead cost $ 58,800 69,000 65,600 $193,400 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 $269,900 of overhead cost in July was maintenance cost. (Hint: to do this, it may be helpful to first determine how much of the $269,900 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 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 47,000 machine-hours