ERS Inc. maintains and repairs office equipment. ERS had an average of 10,000 shares of common stock outstanding for the year. The following income statement account balances are available for ERS at the end of 2013.

Advertising expense	$24,190
Depreciation expense (on service van)	16,240
Income taxes expense	15,150
Interest expense	10,100
Rent expense	58,400
Insurance expense	11,900
Salaries expense (for administrative personnel)	195,600
Service revenue	934,300
Supplies expense	66,400
Utilities expense	26,100
Wages expense (for service technicians)	448,300 Conceptual Connection: Compute net profit margin for ERS. Round your answer to two decimal places.