Questions 1-4 please

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 $ 177,800 $ 154,400 $ 201,200 $ 224,600 Assume that the total overhead cost above 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 $ 38,500 57,000 58,900 $154,400 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 $224,600 of overhead cost in July was maintenance cost. (Hint: to do this, it may be helpful to first determine how much of the $224,600 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 40,000 machine-hours