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The most prominent example of a mesokurtic distribution is the normal distribution family, regardless of the values of its parameters. A few other well-known distributions can be mesokurtic, depending on parameter values: for example, the binomial distribution is mesokurtic for p = 1 / 2 ± 1 / 12 {\textstyle p=1/2\pm {\sqrt {1/12}}} .
The fourth central moment is a measure of the heaviness of the tail of the distribution. Since it is the expectation of a fourth power, the fourth central moment, where defined, is always nonnegative; and except for a point distribution, it is always strictly positive. The fourth central moment of a normal distribution is 3σ 4.
The simplest case of a normal distribution is known as the standard normal distribution or unit normal distribution. This is a special case when μ = 0 {\textstyle \mu =0} and σ 2 = 1 {\textstyle \sigma ^{2}=1} , and it is described by this probability density function (or density): φ ( z ) = e − z 2 2 2 π . {\displaystyle \varphi (z ...
For fourth order moments (four variables) there are three terms. ... Hence the multivariate normal distribution is an example of the class of elliptical distributions.
In probability theory and statistics, a central moment is a moment of a probability distribution of a random variable about the random variable's mean; that is, it is the expected value of a specified integer power of the deviation of the random variable from the mean. The various moments form one set of values by which the properties of a ...
For the case of a d-variate normal distribution ... For example, let [] be a sample of ... The first term is the fourth moment about the mean and has value ...
Therefore, all of the cokurtosis terms of this distribution with this nonlinear correlation are smaller than what would have been expected from a bivariate normal distribution with ρ=0.818. Note that although X and Y are individually standard normally distributed, the distribution of the sum X+Y is platykurtic. The standard deviation of the sum is
For example, it can be used to ... using the third and fourth moments of the distribution. ... it follows that for a normal distribution at least 95% lies within ...