The range fails miserably as a proper measure of variability. These videos will show you why that is, and how a new (more complicated) approach give us much better method.
- Why Measure Variability?
- The Range
Variance and Standard Deviation
- Deviations From The Mean
- The Variance (to the rescue!)
- The Standard Deviation
- Example | Deviations From The Mean
- Example | Variance
- Example | Standard Deviation (plus checking your answers)
- Sum of Squares | Computational vs Definitional Formulas
- Sample Variance and Sample Standard Deviation
- Using the Standard Deviation to Visualize a Distribution
- What is a Biased Estimator?
- How Changing the Data Affects a Standard Deviation