Bracken Clinic uses client-visits as its measure of activity. During September, the clinic budgeted for 2,100 client-visits, but its actual level of activity was 2,140 client-visits. The clinic has provided the following data concerning the formulas used in its budgeting and its actual results for September: Data used in budgeting: Fixed element per month Variable element per client-visit Revenue $ 44.50 Personnel expenses $ 26,100 $ 12.60 Medical supplies 600 7.20 Occupancy expenses 6,500 2.40 Administrative expenses 3,100 0.10 Total expenses $ 36,300 $ 22.30 Actual results for September: Revenue $ 93,240 Personnel expenses $ 50,754 Medical supplies $ 15,328 Occupancy expenses $ 11,646 Administrative expenses $ 3,394 The revenue variance for September would be closest to: