How do you know whether a number is a parameter or a statistic?
To figure out whether a given number is a parameter or a statistic, ask yourself the following:
- Does the number describe a whole, complete population where every member can be reached for data collection?
- Is it possible to collect data for this number from every member of the population in a reasonable time frame?
If the answer is yes to both questions, the number is likely to be a parameter. For small populations, data can be collected from the whole population and summarized in parameters.
If the answer is no to either of the questions, then the number is more likely to be a statistic.