In this case, the sample is the 200 students, while the population is all test takers in the region. Example: Standard error vs standard deviationIn a random sample of 200 students, the mean math SAT score is 550. In contrast, the standard error is an inferential statistic that can only be estimated (unless the real population parameter is known). The standard deviation is a descriptive statistic that can be calculated from sample data.
Standard error matters because it helps you estimate how well your sample data represents the whole population.
In statistics, data from samples is used to understand larger populations. Frequently asked questions about standard error.How should you report the standard error?.