How do I calculate variance in a dataset?

How do I calculate variance in a dataset?

To calculate variance, you first find the mean of your dataset, then subtract the mean from each data point, square the result, and finally average those squared differences.

Can you show me an example with numbers?

Sure! Let's say your dataset is [4, 8, 6, 5, 3]. The mean is 5.2. The squared differences are [(4-5.2)², (8-5.2)², (6-5.2)², (5-5.2)², (3-5.2)²] which equals [1.44, 7.84, 0.64, 0.04, 4.84]. The variance is the average of these squared differences.

What is the variance for that dataset?

The variance for the dataset [4, 8, 6, 5, 3] is (1.44 + 7.84 + 0.64 + 0.04 + 4.84) / 5 = 2.96.

Is there a difference between population variance and sample variance?

Yes, population variance uses 'N' (the total number of data points) in the denominator, while sample variance uses 'N-1' to account for sample size.