Denapasa Manufacturing Leases a Vacuum Cleaning System for a Basic

Denapasa Manufacturing leases a vacuum cleaning system for a basic monthly fee plus an additional cost per hour used above a given minimum for each month. Given below is the information for the most recent six-month period on the number of machine hours of use and the total cost under this lease.
$\begin{array}{|l|l|l|}\hline \text { Montl } & \text { Macluine Hours } & \text { Total Cost } \\ \hline 7 & 6,300 & \$ 58,200 \\\hline 8 & 4,400 & 49,935 \\\hline 9 & 4,700 & 52,390 \\\hline 10 & 5,200 & 54,440 \\\hline 11 & 5,600 & 56,620 \\\hline 12 & 5,000 & 53,800 \\\hline\end{array}$ You are to provide information for planning on the variable and fixed cost elements in this lease. Use the high-low method to (a) determine the variable cost per machine hour and (b) compute the fixed and variable costs for months 7 and 8.