Z (Normal) Distribution for the Probability Distribution Calculator

Density Function. The normal distribution function is determined by the following formula:

f(x) = 1/[s(2p)1/2] * e{-1/2*[(x-m)/s]^2}

-∞ < x < ∞



is the mean


is the standard deviation


is the base of the natural logarithm, sometimes called Euler's e (2.71...)


is the constant Pi (3.14...)

Z. This field displays the current variate value for the Z (Normal) distribution. When you edit this value (either manually or with the microscrolls), Statistica computes the associated p-value for the specified parameters.

p. This field displays the p-value computed from the specified variate value and parameters or you can enter a desired p-value (either manually or edit the existing value with the microscrolls) and compute the critical value of the distribution for the specified parameters.

Mean, st. dev. Specify here the location and scale parameters of the distribution, mean and standard deviation, respectively. If one or both of these parameters are changed, then the p-value will be recomputed based on the respective variate value.