The population mean, or population expected value, is a measure of the central tendency either of a probability distribution or of a random variable characterized by that distribution.

The population means is the mean or average of all values in the given population. It is calculated by the sum of all values in the population, denoted by the summation of X divided by the number of population values denoted by N. It arrives by summing up all the observations in the group and dividing the summation by the number of observations.

population mean (plural population means) (statistics) The mean (usually arithmetic, but possibly geometric) of all members of a population or all possible values from which a sample can be taken, as opposed to a sample mean.