Question

What does a z-score measure?

Answer 1

Simply put, a z-score is the number of standard deviations from the mean a data point is. But more technically it's a measure of how many standard deviations below or above the population mean a raw score is. A z-score is also known as a standard score and it can be placed on a normal distribution curve.

The z-score basically converts an individual raw score into a new score that shows how it compares to the mean. Once we have a z-score for one value, it becomes easier to compare it to other values. Let’s take a look at the formula