1.9.D—Calculate z-scores with population parameters

Calculate z-scores with population parameters.

• A standardized score measures the number of standard deviations a data value falls above or below the mean.
• A z-score is calculated as xi - μ σ , where xi is the data value, µ is the population mean, and is the population standard deviation. A z-scor σ e measures how many standard deviations a data value is above (positive z-score) or below (negative z-score) the mean. When the population mean and standard deviation are unknown, the sample mean and standard deviation may be used to determine a z-score.