Kirnon Clinic uses client-visits as its measure of activity. During July, the clinic budgeted for 3,600 client-visits, but its actual level of activity was 3,520 client-visits. The clinic has provided the following data concerning the formulas to be used in its budgeting Fixed Variable element element per per month client-visit $39.89 Revenue Personnel expenses Medical supplies Occupancy expenses Administrative expenses Total expenses $35,800 1,800 8,800 5,800 $52,200 $11.00 7.80 1.80 0.90 $21.50 The activity variance for net operating income in July would be closest to