16
May
Variance Vs Sample Variance. N Number of observations in sample. Sample Variance is calculated in the same manner as population variation and is also denoted by s square s2 just the difference is that in order to calculate sample variance. We have a population that is Normal with a mean of μ and a variance of σ 2We take a sample of size n using simple random samplingThen we form the simple arithmetic mean of the sample values. Lets start with some basics of statistical arithmetic.
When dealing with the complete population the population variance is a constant a parameter which helps to describe the population. This helps the stake holder to be on the safe side while taking decision or for other inferences. Sample variance refers to variation of observations the data points in a single sample. Standard deviation is used to identify outliers in the data. Lets start with some basics of statistical arithmetic. 1n vs 1 n-1.
The i th observation in the sample.
In our example 2 I divide by 99 100 less 1. Population variance refers to the value of variance that is calculated from population data and sample variance is the variance calculated from sample data. To begin with lets consider a standard problem. Variance measures the inconsistency of different predictions using different training sets its not a measure of overall accuracy. In our example 2 I divide by 99 100 less 1. The sample variance formula looks like this.