ChiDistribution

ChiDistribution[ν] represents a chi distribution with ν degrees of freedom.

Examples

Create a chi distribution and compute the mean:

Mean[ChiDistribution[4]]
(* (2 Sqrt[2/Pi] Gamma[5/2])/Gamma[2] *)

Sample from a chi distribution:

RandomVariate[ChiDistribution[3], 5]
(* {1.92, 2.15, 1.78, 2.33, 1.64} *)

Please visit the official Wolfram Language Reference for more details.