What is the definition of a population in statistics?

The definition of a population in statistics refers to the entire set of individuals or items being studied. This encompasses all possible subjects that could be included in a research investigation related to a specific characteristic or set of characteristics. Understanding what constitutes a population is crucial in statistics because it influences how data is collected, analyzed, and interpreted.

In contrast, the other options describe different concepts in statistical research. For instance, a group of individuals selected for a study would represent a sample, which is a subset of the population intended to represent the population as a whole. A summary of characteristics from a data set refers to statistical measures such as mean, median, or mode, and does not define what a population is. Lastly, a single individual or item from a study describes a case or sample point rather than the broader population. In statistical analysis, accurately identifying the population is fundamental to drawing valid inferences and making generalizations based on collected data.