Nova Company$$s total overhead costs at various levels of activity follow:

Month Machine$-$Hours Total Overhead Costs

April $75,000$ $ $208,000$

May $109,500280,000$

June $90,000232,000$

July $100,000247,000$

Assume that the total overhead costs consist of utilities, supervisory salaries, and maintenance. The breakdown of these costs at the $75,000$ machine$-$hour level of activity is as follows:

Utilities $($V$)$ $ $49,000$

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

Maintenance $($M$)137,000$

Total overhead costs $ $208,000$

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

Nova Company$$s 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 $$280,000.$ Determine how much of this consisted of maintenance cost. $($Hint: To do this, it may be helpful to first determine how much of the $$280,000$ 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 high$$low 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 company$$s 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 $70,000$ machine$-$hours? At an operating activity level of $85,000$ machine$-$hours? $($Do not round intermediate calculations. Round your answers to the nearest whole dollar amount.$)$