Pearse Kennel uses tenant-days as its measure of activity; an animal housed in the kennel for one day is counted as one tenant-day. During December, the kennel budgeted for 4,100 tenant-days, but its actual level of activity was 4,080 tenant-days. The kennel has provided the following data concerning the formulas used in its budgeting and its actual results for December:

Data used in budgeting:

	Fixed element per month	Variable element per tenant-day
Revenue		$30.60
Wages and salaries	$3,100	$6.60
Food and supplies	500	11.40
Facility expenses	8,100	3.60
Administrative expenses	7,900	0.60
Total expenses	$19,600	$22.20

Actual results for December:

Revenue	$107,880
Wages and salaries	$23,510
Food and supplies	$36,791
Facility expenses	$19,260
Administrative expenses	$9,142

The net operating income in the planning budget for December would be closest t