AICPA Exam CPA-Auditing Topic 1 Question 70 Discussion

Choice 'b' is correct. A stratified sample generally is more efficient than an unstratified sample since the population is classified in a manner that emphasizes the higher dollar value items. The result is an estimate having a desired level of precision with a smaller sample size.

Choice 'a' is incorrect. Both stratified and unstratified MPU may be used for populations where many monetary errors are expected to occur.

Choice 'c' is incorrect. Stratified sampling reduces the variability among items in a stratum.

Choice 'd' is incorrect. Standard deviations measure variability, and stratification would tend to reduce the strata standard deviations as compared to the overall standard deviation of the population.