How to Calculate Z-Scores (Standardized Scores) Definition, Types, Examples & Uses

How to Calculate Z-Scores (Standardized Scores)

Subject: Mathematics

Book: Maths Mastery

Z-scores show how many standard deviations a data point is from the mean, using z = (x – μ) / σ, where μ is the mean and σ is the standard deviation. A positive z-score means x is above the mean, a negative z-score indicates it is below, and zero indicates x equals the mean. Z-scores streamline comparisons across different scales—for example, comparing test scores from different exams or measuring performance across varied categories. Mastering z-score computation is vital for statistical analysis, enabling normalized data interpretation in scientific research or standardized testing contexts.