Standard Deviation

Analyze data sets by finding the mean and variance.

Formula & Methodology

Standard deviation σ = sqrt( Σ(x − mean)² / N ); variance is the square of the standard deviation.

Worked Example

For the set 2, 4, 4, 4, 5, 5, 7, 9 the standard deviation is about 2.

Frequently Asked Questions

What is standard deviation?

It measures how spread out the values in a data set are around the mean. A larger value means more variation.

What is the difference between sample and population?

A sample divides by N−1, a population by N. Use the sample version when your data is a sample of a larger group.

How do I enter data?

Enter numbers separated by commas or spaces; the calculator computes mean, variance, and standard deviation.

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