Final answer:
A statistic refers to a characteristic of a sample used to estimate a population parameter.
Step-by-step explanation:
A statistic refers to a characteristic of a sample, such as the mean or mode, used as an estimator of a population. It is a numerical characteristic of the sample and is used to estimate the corresponding population parameter. For example, if we consider the average number of points earned by students in one math class as a sample, it represents a statistic that estimates the average for the entire population of math classes.