The figure below plots the density function of a normal distribution with the chosen mean and standard deviation values that is truncated at zero.
The area under the curve represents the cumulative distribution function evaluated at the *X level* chosen.

*Note: clicking on the plot switches between cumulative and tail distribution functions.*

The following functions can be used in *EXCEL* to generate the (untruncated) normal distribution data.
*Note: To incorporate truncation at zero, the functions should be modified appropriately.*

*NORM.DIST(X,mean,sd,0):*computes the probability density function at*X**NORM.DIST(X,mean,sd,1):*computes the cumulative distribution function at*X**1-NORM.DIST(X,mean,sd,1):*computes the tail distribution function at*X*

Mean:

Std. Dev.: