Bartosiewicz Clinic uses client$-$visits as its measure of activity. During January, the clinic budgeted for $3,900$ client$-$visits, but its actual level of activity was $3,880$ client$-$visits. The clinic has provided the following data concerning the formulas used in its budgeting and its actual results for January:

Data used in budgeting:

$\backslash$table$[[,\backslash$table$[[$Fixed element$],[$per month$]],\backslash$table$[[$Variable element$],[$per client$-$visit$]]],[$Revenue$,$$$0,$$$35\mathrm{.}9$