Question

An auditor for a public accounting firm must review a sample of a client's accounts-receivable invoices. The 1,200 invoices are filed by date received in file drawers. A sample of 100 invoices is required. Explain how systematic sampling could be implemented for this audit.

Answer 1

Systematic sampling is a type of probability sampling method in which sample members from a larger population are selected according to a random starting point and a fixed, periodic interval. This interval, called the sampling interval, is calculated by dividing the population size by the desired sample size. Then select a random start between 1 and sampling interval and Repeatedly add sampling interval to select subsequent sample

Population size= 1200

Sample size= 100

Sampling interval= Population size/ sample size= 1200/100= 12

Lets select a random number between 1 and 12.

let it be 10.

so the invoices we select for the sample will be 10, 22, 34, 46....... 1186, 1198