Paulis Kennel uses tenant$-$days as its measure of activity; an animal housed in the kennel for one day is counted as one tenant$-$day. During February, the kennel budgeted for $5,000$ tenant$-$days, but its actual level of activity was $5,020$ tenant$-$days. The kennel has provided the following data concerning the formulas used in its budgeting and its actual results for February:

Data used in budgeting:

$\backslash$table$[[,\backslash$table$[[$Fixed element$],[$per month$]],\backslash$table$[[$Variable element$],[$per tenant$-$day$]]],[$Revenue$,$$$0,$$$31\mathrm{.}50$