Sample variance is a measure of the spread of or dispersion within a set of sample data.The sample variance is the square of the sample standard deviation σ. It is an unbiased estimator of the square of the population standard deviation, which is also called the variance of the population.
x : 4, 8, 2, 9
Sample Variance σ2
Find the value of μ from the given values 4,8,2,9. μ = (4+8+2+9) / 4 μ = 5.75
Let us now calculate the value of (x - μ)2 from the μ value = 5.75
|x||x - μ||(x - μ)2|
Find the ∑(x - μ)2 with the values of (x - μ)2 ∑(x - μ)2 = 3.0625+5.0625+14.0625+10.5625 ∑(x - μ)2 = 32.75 Now, substitute the value of ∑(x - μ)2 and ‘n’ in the formula of Sample Variance σ2 σ2 = 32.75 / 4 σ2 = 8.1875
Learn how to calculate the Sample Population Variance in this tutorial which is given with the definition, formula and example.