Statistics
Normal Distribution Guide
Bell curve explained.
Most important probability distribution.
Properties
- Symmetric, bell-shaped
- Mean=median=mode
- Defined by μ and σ
68-95-99.7
- 68% within ±1σ
- 95% within ±2σ
- 99.7% within ±3σ
Frequently Asked Questions
Normal distribution?
Bell-shaped, symmetric. Defined by mean and SD.
68-95-99.7?
68% within 1SD, 95% within 2, 99.7% within 3.
Z-score?
(Value-Mean)/SD. SDs from mean.