Final answer:
A sample statistic is a numerical descriptive measure of a sample that estimates a population parameter.
Step-by-step explanation:
A sample statistic is a numerical descriptive measure of a sample. It is a number that represents a property of the sample and can be used to estimate a corresponding population parameter. For example, the average number of points earned by students in a math class is a sample statistic that estimates the average for the entire population of math classes. Parameters, on the other hand, are numerical characteristics of the whole population.