CHIINV(p,dof)
p: probability
dof: number of degrees of freedom
The survival function is 1 minus the cumulative distribution function.
If p < 0 or p > 1 or dof < 1 this function returns a #NUM! error.
This function is Excel compatible.
CHIINV(p,dof) is the OpenFormula function LEGACY.CHIDIST(p,dof).