Dodge, CPA, is conducting tests of controls on cash disbursements of Truck Company. Dodge identified the preparation of a voucher and marking it as 'paid' prior to preparing and mailing a check to the vendor as an important control. Based on the importance of this control and the deviation rate observed in prior audits, Dodge established the following parameters:

Risk of overreliance 10 percent

Expected deviation rate 2.50 percent

Tolerable deviation rate 7 percent

For this test of controls, what is considered a 'deviation'?