Standard deviation is the deviation of points from the average value. Standard deviation (S.D) is the square root of variance. The more points disperse away, the higher is the deviation. It is also called as Historical Volatility.
xi = All given values
μ = Mean of all the values
N = number of values
σ = Standard deviation
If x is a random variable, with mean μ = E[x]
Example 1: Six students from a class weigh 53 kg, 63kg, 92kg, 43kg, 39kg, and 64kg. Find the Standard Deviation (Round of to two decimal places).
Step 1: Find Mean for the given data
Step 2: Find the variance, σ²
Step 3: Find the standard deviation, σ