Converting observations from original values to standard deviation units is known as standardizing the data values. This is done in order to get values in such a form where we can compare them. For example, if we have the test scores of two different school and we want to compare the result of the students we have to first convert them into standard deviation units.
Converting the values to standard deviation units is also known as converting the values to z scores.
The formula for the z score is:
[tex]z= \frac{x-u}{s} [/tex]
where x is the data value, which is to be standardized. u is the average of the entire data. s is the standard deviation of the data.
