Crosshill Company's total overhead costs at various levels of activity are presented below: Assume that the overhead cost above consists of utilities, supervisory salaries, and maintenance. The 60,000 -machine-hour level of activity in May is as follows: 2. Using the high-low method, estimate a cost formula for maintenance. (Round the "Va 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 75,000 machine-hours per unit" to 2 decimal places.)