Characteristics of the Normal Distribution

• The 68-95-99.7 Rule

In the normal distribution with mean μ and standard deviation σ,

• Approx. 68% of all observations fall within σ of μ.
• Approx. 95% of all observations fall within 2σ of μ.
• Approx. 99.7% of all observations fall within 3σ of μ.