Standard Deviation

• Standard deviation tells us how spread the data distribution is around mean

[!def] Formula of Standard Deviation
$$
\sigma = \sqrt(\frac{\sum (x-\mu)^2}{N})
$$
As we can see, it is the square root of Variance

• AKA population standard deviation
• This is calculated using all the points from the distribution
• But we dont have all the points and we calculate from the sample dataset, which is called Estimated Standard Deviation
• Standard deviation is square-root of Variance