Nova Companys total overhead costs at various levels of activity follow:

Month	Machine-Hours		Total Overhead Costs
April	77,500		$	213,000
May	114,500			285,000
June	95,000			237,000
July	105,000			246,750

Assume that the total overhead costs consist of utilities, supervisory salaries, and maintenance. The breakdown of these costs at the 77,500 machine-hour level of activity is as follows:

Utilities (V)	$	48,750
Supervisory salaries (F)		22,500
Maintenance (M)		141,750
Total overhead costs	$	213,000

V = variable; F = fixed; M = mixed.

Nova Companys management wants to break the maintenance cost down into its basic variable and fixed cost elements.

Required:

1. As shown, overhead costs in May amounted to $285,000. Determine how much of this consisted of maintenance cost. (Hint: To do this, it may be helpful to first determine how much of the $285,000 consisted of utilities and supervisory salaries. Think about the behaviour of variable and fixed costs!) (Do not round intermediate calculations. Round your answers to the nearest whole dollar amount.)

2. By means of the highlow method, estimate a cost formula for maintenance. (Do not round intermediate calculations. Round "Fixed cost" answer to the nearest whole dollar and "Variable cost" answer to 2 decimal places.)

3. Express the companys total overhead costs in the linear equation form Y = a + bX. (Do not round intermediate calculations. Round "Fixed cost" answer to the nearest whole dollar and "Variable cost" answer to 2 decimal places.)

4. What total overhead costs would you expect to be incurred at an operating activity level of 75,000 machine-hours? At an operating activity level of 90,000 machine-hours? (Do not round intermediate calculations. Round your answers to the nearest whole dollar amount.)