Example · High school
Terms
| Term | This example | Why |
|---|
| variance |
$\frac{(1.5)^2 + (0.5)^2 + (0.5)^2 + (1.5)^2}{4} = \frac{5}{4} = 1.25$
|
The variance of the data $1, 2, 3, 4$ divides the sum $5$ of the squared distances from the mean $2.5$ by the number of data points, $4$.
|
| sample variance |
$\frac{(1.5)^2 + (0.5)^2 + (0.5)^2 + (1.5)^2}{3} = \frac{5}{3} \approx 1.67$
|
The sample variance of the data $1, 2, 3, 4$ divides the sum $5$ of the squared distances from the mean $2.5$ by $4 - 1 = 3$.
|
Distinctions using this example
- Variance vs. sample variance: For the data $1, 2, 3, 4$, the sample variance exceeds the variance by the factor $\frac{4}{3}$, because the sample variance divides by $3$ instead of $4$.
All examples · All distinctions · All definitions