Superior Limited's total overhead costs at various levels of activity are presented below:
Month	Machine Hours	Total Overhead Costs
March	60,000	$216,800
April	50,000	194,000
May	70,000	239,600
June	80,000	262,400
Assume that the overhead costs above consist of utilities, supervisory salaries, and maintenance. At the 50,000 machine-hour level of activity these costs are:
Utilities (V)	$54,000
Supervisory salaries (F)	70,000
Maintenance (M)	70,000
Total overhead costs	$194,000
V = Variable; F = Fixed; M = Mixed.
The company wants to break down the maintenance cost into its basic variable and fixed cost elements.
Required:
a. Estimate the maintenance cost for June. (3 Marks)
b. Use the high-low method to estimate the cost formula for maintenance cost. (4 Marks)
c. Estimate the total overhead cost at an activity level of 55,000 machine hours. (3 Marks)