z-score

Definition

A z-score, also known as a standard score, is a statistical measure that indicates how many standard deviations an individual data point or observation is from the mean of the dataset. It allows us to compare and interpret values in different datasets by measuring their relative position within the distribution.

Analogy

Imagine you and your friends are taking a test. The z-score is like your rank compared to your friends' scores. If you have a high positive z-score, it means you scored above average, while a low negative z-score means you scored below average.

Related terms

Standard deviation: It measures the amount of variability or spread in a dataset.

Normal distribution: Also called Gaussian distribution, it is a symmetrical bell-shaped curve that represents the pattern observed in many natural phenomena.

Percentile rank: It represents the percentage of scores that fall below a specific value in a distribution.