View Full Version : formula for z-score vs percentile

Jan-paul Van Wingerden
12-20-1998, 06:19 PM
Dear BIOMCH readers,

While programming some evaluation sofware I came up with a problem
concerning the use of a cumulative probabilities table.

This is the problem:

To determine the percentile of a normal distribution you have to use a
specific table, the cumulative probabilities table. When plotting this
table as a graph you get a specific curve. The problem is that I cannot
find the formula for this curve (Using such formula makes programming a
lot easier).
I found the cumulative probability function for a continuous uniform
random variable:

y=(x-a)/(b-a) where a