What sampling method ensures that everyone in the population has an equal chance of being selected?

The correct answer is random sampling because this method guarantees that every individual in the entire population has an equal chance of being chosen for the sample. In random sampling, selections are made in such a way that each member of the population has the same probability of being included, which helps eliminate bias and makes the sample more representative of the population.

This method is fundamental in statistical research and surveys because it increases the reliability of the results. When every individual has an equal opportunity to be selected, it increases the likelihood that the sample will reflect the diversity and characteristics of the entire population.

Other sampling methods, like systematic, stratified, and cluster sampling, introduce different techniques and structures that can affect selection probabilities. For example, systematic sampling selects individuals based on a predetermined interval, and stratified sampling divides the population into distinct subgroups before randomly sampling from those groups, which can lead to unequal chances of selection among individuals. Cluster sampling involves dividing the population into clusters and then randomly selecting entire clusters, which again may not give each individual an equal chance of being included.