Mitchum, Inc Using the High-Low Method, Determine:
(1) the Variable Expense Per

Mitchum, Inc. produced different amounts of product X each month as follows:
$$\begin{array} { | l | c | c | } \hline & \text { Units } & \text { Costs } \\\hline \text { April } & 370 & \$ 21,300 \\\hline \text { May } & 420 & \$ 22,050 \\\hline \text { June } & 350 & \$ 21,000 \\\hline \text { July } & 550 & \$ 24,000 \\\hline \text { August } & 450 & \$ 22,500 \\\hline\end{array}$$
Using the high-low method, determine:
(1) The variable expense per unit
(2) The fixed expense
(3) If Mitchum produced 450 units what would total expenses be?