Kaina Clinic uses client$-$visits as its measure of activity. During May, the clinic budgeted for $3,000$ client$-$visits, but its actual level of activity was $2,970$ client$-$visits. The clinic has provided the following data concerning the formulas used in its budgeting and its actual results for May:

Data used in budgeting:

$\backslash$table$[[,$Fixed element per Variable element$],[,$month,per client$-$visit$],[$Revenue$,$$$0,$$$25\mathrm{.}80$