What is sampling risk?
Sampling risk is considered the risk that the sample will not represent the actual population. When conducting tests based on samples, the assumption is that the sample is indicative of the entire population. The auditor should apply professional judgment in assessing sampling risk.
In performing substantive tests of details, the auditor is concerned with two aspects of sampling risk: Risk of incorrect acceptance/ risk of incorrect rejection and the risk of assessing control risk too low/ risk of assessing control risk too high.
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Will sample size increase if the population variability is higher than expected?
Yes, there is a direct relationship between sample size and population variability. Population variability is how similar or dissimilar items in a population are. If the population variability increases, then that means that the items in the population aren’t as similar as the auditor expected. This increases the level of risk, so the audit team […]

Will sample size increase or decrease if the assessed level of risk is higher than expected?
If the assessed level of risk is higher than what the auditor originally determined in the planning phase, then the audit team should increase their sample size or choose a testing method that provides for higher quality evidence.

Will sample size increase or decrease if there is a decrease in the tolerable misstatement?
There is an inverse relationship between sample size and tolerable misstatement, so the sample size would increase if the tolerable misstatement decreases.