The sum of squared standard normal variables will be a variable with this distribution.
The squared Raleigh distribution is a special case of this function. According to Cochran's theorem this is the distribution of the product of the sample size minus one and the sample variance divided by the population variance. The F distribution can be expressed as the ratio of two instances of this distribution. The sum of squared standard normal variables will be a variable with this distribution. A special case of the gamma distribution with scale parameter two, this distribution is the basis for a test that calculates the test statistic by taking the sum of the squared differences of the observed and expected values and dividing by the expected value; that test is often used to test for goodness of fit, and in particular is used to test frequency deviations from the Hardy-Weinberg Principle. For 10 points, name this statistical distribution that is the basis for a hypothesis test named after Pearson.
The squared Raleigh distribution is a special case of this function.
chi-squared distribution [prompt on gamma distribution before it is read]