| Inverse-**chi**-**square** **distribution** - Wikipedia, the free encyclopedia |

| | That is, if X has the **chi**-**square** **distribution** with Î½ degrees of freedom, then according to the first definition, 1 / X has the inverse-**chi**-**square** **distribution** with Î½ degrees of freedom; while according to the second definition, Î½ / X has the inverse-**chi**-**square** **distribution** with Î½ degrees of freedom. |

| | In probability and statistics, the inverse-**chi**-**square** **distribution** is the probability **distribution** of a random variable whose inverse has a **chi**-**square** **distribution**. |

| | It is also often defined as the **distribution** of a random variable whose inverse divided by its degrees of freedom is a **chi**-**square** **distribution**. |

| en.wikipedia.org /wiki/Inverse-chi-square_distribution (414 words) |