Kirnon Clinic uses client-visits as its measure of activity. During July, the clinic budgeted for 3,450 client-visits, but its actual level of activity was 3,400 client-visits. The clinic has provided the following data concerning the formulas to be used in its budgeting: Fixed element per month Variable element per client-visit Revenue $ 0 $ 39.50 Personnel expenses $ 35,500 $ 10.70 Medical supplies 1,500 7.50 Occupancy expenses 8,500 1.50 Administrative expenses 5,500 0.60 Total expenses $ 51,000 $ 20.30 The activity variance for net operating income in July would be closest to