From GeoGebra Manual
- InverseChiSquared[ <Degrees of Freedom>, <Probability> ]
- Computes the inverse of cumulative distribution function of Chi squared distribution at probability p, where the Chi squared distribution has given d degrees of freedom.
- In other words, finds t such that P(X ≤ t) = p, where X is Chi squared random variable.
- Probability p must be from [0,1].