However, the true distribution is often unknown and a proper null distribution ought to be used to represent the data. For example, one sample and two samples tests of means can use t statistics which have Gaussian null distribution, while F statistics, testing k groups of population means, which have Gaussian quadratic form the null distribution.
In reality, the true distribution is frequently unknown, and an accurate null distribution should be utilized to depict the data. For example, one-sample and two-sample tests of means can employ t statistics that follow a Gaussian null distribution, whereas F statistics, testing k groups of population means, which have a Gaussian quadratic form null distribution.