Anxiety can often make these related conditions worse, so talk with a mental health care professional if anxiety begins to interfere on a daily basis.
In probability theory and statistics, the variance of a random variable is a measure of its statistical dispersion, indicating how far from the expected value its values typically are. The variance of a real-valued random variable is its second central moment, and it also happens to be its second cumulant.
Variance is a statistical measure that tells us how measured data vary from the average value of the set of data. In other words, variance is the mean of the squares of the deviations from the arithmetic mean of a data set. 1  Variance is the square of the standard deviation.  The formula for variance is.