26 WORKING WITH SAMPLE DATA Standardizing Individual Data Values on a Normal Curve Not all variables are normally distributed. Many events we can think of are skewed, like personal income or residential housing prices. How- ever, if a variable is normally distributed, we can analyze its distribution through the standard normal distribution using the following equation: Converting a Value to the Standard Normal Distribution where the z- score is the distance an individual value is away from its mean in terms of its standard deviation. Let's consider an example.