Parameter

Definition

A parameter is a numerical characteristic of a population, such as a mean or standard deviation. It represents an entire group rather than a sample taken from it.

5 Must Know Facts For Your Next Test

1. Parameters describe characteristics of populations, while statistics describe samples.
2. Common parameters include the population mean ($\mu$), population variance ($\sigma^2$), and population proportion (P).
3. Parameters are usually unknown because it's often impractical to measure an entire population.
4. Estimates of parameters are derived from sample statistics through inferential statistics.
5. The accuracy of parameter estimates depends on the size and representativeness of the sample.

Review Questions

• What distinguishes a parameter from a statistic?
• Why are parameters typically unknown in practice?
• How do statisticians estimate parameters?

Related terms

Statistic: A numerical value that represents a characteristic of a sample, such as the sample mean or sample standard deviation.

Population: The entire group that is the subject of a statistical study, about which information is desired.

$\mu$ (Mu): $\mu$ represents the population mean, which is the average value of all observations in the population.