Certified Internal Auditor Practice Test 2025 – Complete Exam Prep

In attribute sampling, the determination of sample size is closely related to the estimated occurrence rate of the attribute being tested. When the estimated occurrence rate decreases, it indicates a lower likelihood that the attribute will be found in the sample.

This lower occurrence rate typically leads to a smaller sample size requirement because the objective of sampling is to achieve a specified level of confidence in the results with a manageable number of observations. A less frequent attribute can be effectively inferred with fewer samples, assuming the same confidence level and acceptable error rates.

Therefore, as the estimated occurrence rate decreases while all other factors remain constant, the sample size needed to obtain reliable results reduces correspondingly. This relationship is grounded in statistical principles, where lower probabilities associated with the attribute lead to decreased variability and risk in estimating the population parameters.