Ximpledu

Variance, Standard Deviation

See how to find the variance, standard deviation of the given values.
3 examples and their solutions.

Variance, Standard Deviation

Formula

V(X) = (x1 - x)2 + (x2 - x)2 + (x3 - x)2 + ...n
σ(X) = √V(X)
V(X): Variance
σ(X): Standard deviation
x: Mean

V(X) and σ(X) shows
how far the values are from the mean.

Greater V(X), σ(X):
The values are far from the mean.
Less V(X), σ(X):
The values are far from the mean.

Example

60, 70, 80, 90, 100

1. Variance = ?
2. Standard deviation = ?
Solution

Example

70, 75, 80, 85, 90

1. Variance = ?
2. Standard deviation = ?
Solution

Example

ScoreFrequency
01
11
24
37
45
52


1. Variance = ?
2. Standard deviation = ?
Solution