A simple random sample is defined as...

A simple random sample is defined as...

• A. A sample of size n selected from the population with biased probability
• B. A sample of size n selected so that each possible sample of size n has an equal chance of being selected
• C. A sample of entire population
• D. A sample drawn by clustering

Answer: (B)

Simple random sampling means every possible sample of size n from the population is equally likely to be chosen. This symmetry ensures no systematic bias and that each individual has the same chance of being included (n out of N), which makes the sample representative in expectation and allows clean probability-based inferences about the population. This differs from biased sampling, where some samples are more likely than others; from a census, which includes everyone rather than a subset; and from clustering, which selects groups first rather than individuals with equal likelihood.

Simple random sampling means every possible sample of size n from the population is equally likely to be chosen. This symmetry ensures no systematic bias and that each individual has the same chance of being included (n out of N), which makes the sample representative in expectation and allows clean probability-based inferences about the population.

This differs from biased sampling, where some samples are more likely than others; from a census, which includes everyone rather than a subset; and from clustering, which selects groups first rather than individuals with equal likelihood.