Crosshill Company$$s total overhead costs at various levels of activity are presented below:

Month Machine$-$Hours Total Overhead Cost

April $76,000$ $ $158,000$

May $66,000$ $ $150,000$

June $86,000$ $ $363,000$

July $95,000$ $ $202,000$

Assume that the overhead cost above consists of utilities, supervisory salaries, and maintenance. The breakdown of these costs at the $66,000-$machine$-$hour level of activity in May is as follows:

Utilities $($variable$)$ $ $39,000$

Supervisory salaries $($fixed$)22,000$

Maintenance $($mixed$)89,000$

Total overhead cost $ $150,000$

The company wants to break down the maintenance cost into its variable and fixed cost elements.

Required:

$1.$ Estimate how much of the $$202,000$ of overhead cost in July was maintenance cost. $($Hint: To do this, first determine how much of the $$202,000$ consisted of utilities and supervisory salaries. Think about the behaviour of variable and fixed costs within the relevant range.$)($Round the "Variable cost per unit" to $2$ decimal places.$)$

$2.$ Using the high$$low method, estimate a cost formula for maintenance. $($Round the "Variable cost per unit" to $2$ decimal places.$)$

$3.$ Express the company$$s total overhead cost in the form Y $=$ a $+$ bX$.($Round the "Variable cost per unit" to $2$ decimal places.$)$

$4.$ What total overhead cost would you expect to be incurred at an activity level of $81,000$ machine$-$hours? $($Round the "Variable cost per unit" to $2$ decimal places.$)$