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.
The variance of the mean of the clustered sample is bigger by a factor [1 + (n â 1)Ï], which is sometimes called the sample design effect (Kish 1965) or, more descriptively, the variance inflation factor.