Z-Score: Definition, Formula, Calculation & Interpretation Standard Normal Distribution (SND). The SND (i.e., z-distribution) is always the same shape as the raw score Practice Problems for Z-Scores. Scores on a psychological well-being scale range from 1 to 10, with an average score of What is Z-Score? Z-score also known as the standard score gives us an idea of how far a data point is from the mean. It indicates how many standard deviations an element is from the mean. Hence, Z-Score is measured in terms of standard deviation from the mean. BoJvsKy.