The difference exhibited by data points within a data set, as related to each other or as related to the mean. Three key measurements of variability are:
- Range: The difference between the highest and lowest values in a dataset. Shows the spread of the data. (Formula: Maximum Value – Minimum Value)
- Variance: The average squared deviation of all values from the mean. Measures how spread out the data is. (Formula: Σ(x – μ)² / n)
- Standard Deviation (SD): The square root of the variance. Represents the average distance from the mean. (Formula: √(Σ(x – μ)² / n) )
