Probability ↓↑
Data Science ↓↑
Data Engineering ↓↑
Vector and Matrix
Machine Learning ↓↑
Natural Language Processing ↓↑
Computer Vision ↓↑
Interview Questions ↓↑

# Standard Deviation

Standard Deviation is a measure of how spread out numbers are.

It is the square root of the Variance. It is often more convenient than the variance because it has the same unit as the data points.

Population Standard Deviation, $\sigma=\sqrt{\frac{1}{n}}\sum_i^n(x_{i}-\mu)^2$

Sample Standard Deviation, $\sigma=\sqrt{\frac{1}{1-n}}\sum_i^n(x_{i}-\overline{x})^2$