This equation computes the z-score of a data set.  A z-score, or standard score, is the number of standard deviations a data point is from the data set's mean. The z-score is a measure of how many standard deviations below or above the population mean a raw score lies.

The z-score is the signed number (is positive when the raw score is larger than the mean) of standard deviations an observation or data point is above the mean value of the data set.  The z-score is a dimensionless quantity obtained by subtracting the population mean from an individual raw score and then dividing the difference by the population standard deviation. 

See Also

• Try the Mean calculation
• Try the Median calculation
• Try the Mode calculation
• Here's the Range of a data set
• Here's the Min calculation
• And the Max calculation
• Standard Deviation (Sample)
• Standard Deviation (Population)
• Frequency Distribution between min and max
• Frequency Distribution for population
• Try the z-score calculation on your data set
• Try the z-score when you know both mean and SD