🎲

Variance and Standard Deviation

★★★☆☆High School

📖Definition

Variance measures how spread out data is from the mean. Standard deviation is the square root of variance.

Var(X) = E[(X - μ)²] = E[X²] - (E[X])²

Variance definition

σ = √Var(X)

Standard deviation

Var(aX + b) = a² Var(X)

Variance property

예제 1

Find the variance of {1, 2, 3, 4, 5}.

Investment risk measurement

Product consistency

Measurement error analysis

#분산#표준편차#variance#standard deviation