Statistics Calculator

The statistics calculator includes three parts:
(1) From N data to obtain statistics x_mean (xm), SD, and skewness
In which,
mean value xm = Σ(xi)/n, xi = x1, x2, …, xn
standard deviation sigma SD = {[Σ(xi-xm)^2)]/(n-1)}^(0.5)
skewness SK = {[Σ(xi-xm)^3)]*n/(n-1)/(n-2)}/(SD^3)
(2) From standard normal deviation Z to obtain cumulative distribution function CDF(Z)
It is noted that the calculation is based on the standard normal distribution.
(3) From cumulative distribution function CDF(Z) to obtain standard normal deviation Z
Again, it is noted that the calculation is based on the standard normal distribution.