This allows for statistical tests that rely on the normal distribution, such as hypothesis testing and estimations of confidence intervals. The z-score is used to identify outliers in a dataset.

Investors use the normal probability distribution of a stock's past returns ... Test scores that are extreme outliers, such as a score of 100 or 0, would be considered long-tail data points ...

It can indicate whether or not your data adheres to a normal distribution. It’s okay for your data to have skewness, it can indicate outliers in your data set. If your data demonstrates skewness ...