What term is used to describe the variability of the population mean?

The term that describes the variability of the population mean is the standard error of the mean. This statistic provides insight into how much the sample mean is expected to vary from the true population mean. It is calculated by dividing the standard deviation of the sample by the square root of the sample size. As the sample size increases, the standard error decreases, indicating that estimates of the population mean become more reliable.

The standard deviation is a measure of the variability or dispersion of individual data points within a sample, rather than the variability of the mean itself. Variance is similar to standard deviation but represents the squared deviation from the mean and does not directly indicate how sample means vary. A confidence interval gives a range of values that is likely to contain the population mean, reflecting the precision of the estimate but does not specifically quantify the variability of the mean itself.