2- Understanding Variance

Ankit Gupta
Sep 9, 2018 · 2 min read

Variance- It is the average of squared of distance from the mean.

Variance

Let us look at the figure Variance Example I. Here, the number of data points are 6 with each data point as 100.

The mean is 100 and Variance is 0 as shown in the below calculation.

Variance Example I

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Now, let’s change one to the data points to 102 as shown in the fig Variable Example II. The mean has increased to 100.33 and Var is 0.56 as shown in the below calculation.

Variance Example II

Population Variance- It is the average of squared of distance from the population mean.

Population Variance

Sample Variance- It is the average of squared of distance from the sample mean. It is denoted by s-square

Sample Variance

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