Certified Quality Auditor (CQA) Prasctice Exam

Which two conditions must be met to infer the statistical significance of an audit sample?

1. The population must be homogeneous and the sample size must be greater than 10

2. The population must be homogeneous and the sample must be random

3. The sample size must be greater than 10 and the sample must be random

4. The sample must be from multiple locations and greater than 10

The correct answer is: The population must be homogeneous and the sample must be random

To infer the statistical significance of an audit sample, it is crucial that the population is homogeneous and that the sample is selected randomly. A homogeneous population means that the items within the population are similar in key characteristics relevant to the audit process, which enhances the reliability of inferences drawn from the sample about the larger group. If the population is not homogeneous, the sample may not accurately represent the diversity in the population, leading to skewed results. Additionally, having a random sample ensures that every member of the population has an equal chance of being selected, minimizing selection bias and allowing for results to be generalized back to the entire population. Random sampling helps to ensure that the sample is representative of the population as a whole, which is essential for making valid statistical inferences. Together, these two conditions create a strong foundation for accurate and meaningful statistical analysis in an auditing context.