Statistic

Definition

A statistic is a numerical value that summarizes or describes a characteristic of a sample. It is used to make inferences about populations based on sampled data.

5 Must Know Facts For Your Next Test

1. Statistics can be measures of central tendency (mean, median, mode) or measures of dispersion (range, variance, standard deviation).
2. Statistics are calculated from sample data and are used to estimate population parameters.
3. The difference between a statistic and a parameter is that statistics describe samples while parameters describe populations.
4. Common examples of statistics include the sample mean ($\bar{x}$), sample proportion ($\hat{p}$), and sample variance ($s^2$).
5. Inferential statistics use sample statistics to make predictions or inferences about a population.

Review Questions

• What is the primary purpose of calculating statistics from a sample?
• Name two types of statistical measures and give an example of each.
• How does a statistic differ from a parameter?

Related terms

Parameter:

A numerical value that describes a characteristic of an entire population.

Sample:

A subset of individuals or observations selected from a larger population for the purpose of statistical analysis.

Population:

The entire group of individuals or observations that researchers are interested in studying.