Z-Score

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Calculate

Example: on an exam with a mean of 70 and a standard deviation of 8, a student scored 82. How far above the mean are they? Change the values to work out your own case.

Observation X Mean μ Standard deviation σ

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What each term means

Z-Score (Z): Measures how far a data point is from the mean, in standard deviations. A positive z-score means the point is above the mean; a negative one, below.
Observed Value (X): The specific data point or value you are evaluating.
Population Mean (μ): The mean of all data points in the population the sample was drawn from.
Population Standard Deviation (σ): Measures how spread out the data are in the population. It is the square root of the variance.