What should an auditor do when performing random sampling in an interval of 5000?

When performing random sampling in an interval of 5000, selecting every nth account based on that interval is the correct approach. This method ensures that the sample is representative of the population by systematically selecting samples at regular intervals.

In this scenario, using an interval of 5000 means that the auditor will choose accounts efficiently throughout the population, capturing a broad range and reducing bias in selection. It allows for a structured sampling method that can help auditors ensure that no specific group of accounts is being unfairly favored or overlooked.

Choosing every account with a number ending in zero would not provide a random sample, as it could introduce bias by only considering accounts that fit a specific pattern. Starting with any account number does not inherently define a methodical approach to sampling, which may lead to unintended biases as well. Selecting only high-value accounts also goes against the principle of random sampling, as it would skew the sample towards high-value accounts and ignore the rest of the population, ultimately compromising the validity of the audit findings.

Therefore, systematically selecting every nth account based on the specified interval of 5000 is the most effective and unbiased way to conduct the sampling, preserving the integrity and representativeness of the sample.