Final answer:
Classical variables sampling does not require an estimate of the standard deviation of the population's recorded amounts, which is a key difference from monetary-unit sampling and is also likely to be simpler regarding the inclusion of zero and negative balances.
Step-by-step explanation:
The student asked which advantage classical variables sampling has over monetary-unit sampling. Among the options provided, number 1, that an estimate of the standard deviation of the population's recorded amounts is not required, could be considered an advantage of classical variables sampling. Unlike monetary-unit sampling, classical variables sampling does not depend on the population's value distribution, as it assesses the sample by attributes or occurrence rather than by monetary quantification which would require a better understanding of the variation (standard deviation). Classical variables sampling might not need to consider zero and negative balances in a specialized manner, which simplifies the sampling design, aligning with option 3.
In terms of sampling concepts, sampling variability refers to how sample statistics can vary from one sample to another even within the same population. This variability is influenced by sample size, with larger sizes generally leading to smaller variability and therefore more reliable statistics. The importance of sample size is supported by the fact that large sample sizes are more likely to produce statistics that are closer to actual population parameters.