This function takes a random sample and produces an unbiased estimate of the squared variance based on the U-statistic $sum_k1 ne k2 ne k3 ne k4 (x_k1-x_k2))^2 (x_k3-x_k4))^2$.
is a vector of i.i.d. observations.
unbiased estimate of squared variance $sigma^4$, where $sigma^2$ is the variance.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.