BGIM

Probability Function CalculatorS. Purcell.This site is designed to provide a calculator for the chisquared and normal distributions. See below for notes on how to use the forms.
X : critical value for statistic P(X>x) : probability of being above the critical value df : degrees of freedom NCP : noncentrality parameter For central chisquared distribution, NCP = 0. i.e. df=1, P(X>x) = 0.05, NCP = 0 gives X = 3.84146 For standard normal distribution, mean = 0, sd = 1 i.e. mean = 0, sd = 1, P(X>x) = 0.025 give X = 1.95996 