What is a standard error?
Answer: Standard error is a statistical term that measures the accuracy with which a sample represents a population. A standard error is the standard deviation of the sampling distribution of a statistic. In statistics, samples mean deviates from the actual mean of a population; this deviation is the standard error. The standard error of the mean (SEM) measures how far the sample mean (average) of the data is likely to be from the true population mean. The SEM is always smaller than the standard deviation (SD).