Question

How to get variance
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Answer 1

To calculate the variance of a data set, find the mean, subtract the mean from each data point, square the differences, add up the squared differences, and divide by the number of data points minus 1.

Step-by-step explanation:

Variance is a measure of how spread out the data points are in a data set. To calculate the variance, follow these steps:

1. Find the mean (average) of the data set.
2. Subtract the mean from each data point and square the result.
3. Add up all the squared differences.
4. Divide the sum by the number of data points minus 1.

For example, if we have a data set with values 3, 6, 9, and 12, the steps would be:

1. Mean = (3 + 6 + 9 + 12)/4 = 7.5
2. (3-7.5)^2 = 20.25, (6-7.5)^2 = 2.25, (9-7.5)^2 = 2.25, (12-7.5)^2 = 20.25
3. Sum = 20.25 + 2.25 + 2.25 + 20.25 = 45
4. Variance = 45/(4-1) = 15