The controller of Ivanhoe Industries has collected the following monthly cost data for use in analyzing the behavior of maintenance costs.

$\backslash$table$[[$Month$,\backslash$table$[[$Total$],[$Maintenance Costs$]],\backslash$table$[[$Total$],[$Machine Hours$]]],[$January$,$$$3,041,4,032],[$February$,3,456,4,608],[$March$,4,147,6,912],[$April$,5,184,9,101],[$May$,3,686,5,760],[$June$,5,633,9,216]]$

$($a$1)$

Determine the unit variable costs using the high$-$low method for this mixed cost. $($Round answer to $2$ decimal places e$.$g$.2\mathrm{.}25.)$

Variable cost per machine hour $