The Curve of our Population Sample:
An alternative to doing the labor intensive calculations is to use the program Microsoft Excel, which also has graphical capabilities.
Using Microsoft Excel
One can easily perceive the utility of the Normal curve: for any given height, one can find the frequency of individuals within the population of that height. Additionally, the area under the curve equals the frequency at which individuals of that height appear in the population. Suppose that it was necessary to find the frequency of individuals with heights between 64 and 71 inches. We would need to find the area of the distribution between the x-values 64 and 71. This can be accomplished by finding the z-Distribution.