Link: Probability distribution
What is normal distribution?
A bell shape curve. Also called Gaussian distribution.
We need to know standard deviation and mean to draw the curve.
Standard deviation
The width of the curve. The smaller standard deviation = narrower and taller curve.
- 2/3 (68%) data within 1 sd of the mean
- 95% data within 2 sd of the mean
- 99.7% data within 3 sd
Usage of normal distribution
Lots of scenarios follows normal distribution. The reason is Central limit theorem.