What does sigma means in the formula of mean value?

In the context of the formula for the mean value, sigma (σ) typically represents the standard deviation of a set of data. The mean is calculated as the sum of all data points divided by the number of points, while the standard deviation quantifies the amount of variation or dispersion in the data set. In some cases, sigma can also refer to the summation symbol (Σ), which indicates the total sum of a series of values. The specific meaning depends on the context in which the formula is used.