The z-score (also known as the standard score) measures how many standard deviations a data point is from the mean of a dataset. It helps determine whether a data point is typical or unusual compared to the dataset.
The formula for the z-score is:
z = \frac{x - \mu}{\sigma}
Where: • x = the value being evaluated • \mu = the mean of the dataset • \sigma = the standard deviation of the dataset
Interpretation: • A positive z-score indicates the data point is above the mean. • A negative z-score indicates the data point is below the mean. • A z-score of 0 means the data point is exactly at the mean.