example digits=2: (0.001234 => 0.0012)

numerator degrees of freedom

denominator degrees of freedom

Choose X or P(x≤X)

Message

F (Fisher Snedecor) distribution is used for a normally distributed population.

Let Z_{1}, Z_{2},....Z_{n} be independent standard random variables.

Let X_{1} = [Z_{1}^{2} + Z_{2}^{2} +....+ Z_{n}^{2}].

Let Z'_{1}, Z'_{2},....Z'_{n} be independent standard random variables.

Let X_{2} = [Z'_{1}^{2} + Z'_{2}^{2} +....+ Z'_{m}^{2}].

Let X = (X_{1}/n) / (x_{2}/m).

X distribute as **F** random variable with **n** degrees of freedom (numerator) and **m** degrees of freedom (denominator)

X_{1} distribute as a chi-square random variable with **n** degrees of freedom.

X_{2} distribute as a chi-square random variable with **m** degrees of freedom.

Example of use: ANOVA test, F test for variances comparison.