Creating a Normal Probability Plot with Excel 2007

A normal probability plot is a statistical tool used to help determine if values of some variable reasonably comes from a normal distribution. In this context, we look at the residuals from a multiple regression analysis to check whether the assumption of normality is reasonable. The straighter the points line up in the scatterplot of residuals vs. normal scores (z-scores) the more faith we have that they came from a normal curve.