Understanding fundamental concepts in sampling techniques

In Chapter 2, Essential Statistics for Data Assessment, I emphasized that statistics such as mean and variance were used to describe the population. The intent is to help you distinguish between the population and samples. With a population at hand, the information is complete, which means all statistics you calculated will be authentic since you have everything. With a sample, the information you have only relates to a small portion, or a subset of the population.

What exactly is a population?

A population is the whole set of entities under study. If you want to study the average monthly income of all American women, then the population includes every woman in the United States. Population will change if the study or the question changes. If the study is about finding the average monthly income of all Los Angeles women, then a subset of the population for the previous study becomes the whole population of the current...