# Calculate: Standard Deviation

November 5, 2008 by kltangen

Filed under Dispersion, How To Calculate

Regardless of how you obtained variance (by dividing by N or by N-1), you calculate the standard deviation by taking the square root of variance.

Take what you calculated variance to be. Put it in your calculator and push this button:

The result is the standard deviation.

NOW YOU CHOOSE:

Day 3: Dispersion

A Bit More About Dispersion

Even More About Dispersion

Range

MAD

Sum of Squares

Variance

Standard Deviation

How To Calculate

Range

MAD

Sum of Squares

Variance

Standard Deviation

Formulas For Dispersion

Practice Problems

More Practice Problems

Basic Facts About Dispersion

Vocabulary

Quiz 3

Summary

# Calculate: Variance

November 5, 2008 by kltangen

Filed under Dispersion, How To Calculate

The fourth measure of dispersion is variance. Variance is the Sum of Squares divided by N

Variance of a population is always SS divided by N; regardless whether it is a large population or a small population.

Variance of a large sample (where N is equal to or larger than 30) is calculated like a population. Divide SS by N.

If the sample is small (less than 30), adjust for the small sample size by dividing SS by N-1.

NOW YOU CHOOSE:

Day 3: Dispersion

A Bit More About Dispersion

Even More About Dispersion

Range

MAD

Sum of Squares

Variance

Standard Deviation

How To Calculate

Range

MAD

Sum of Squares

Variance

Standard Deviation

Formulas For Dispersion

Practice Problems

More Practice Problems

Basic Facts About Dispersion

Vocabulary

Quiz 3

Summary

# Calculate: MAD

November 5, 2008 by kltangen

Filed under Dispersion, How To Calculate

Day 3: Dispersion

A Bit More About Dispersion

Even More About Dispersion

Range

MAD

Sum of Squares

Variance

Standard Deviation

How To Calculate

Range

MAD

Sum of Squares

Variance

Standard Deviation

Formulas For Dispersion

Practice Problems

More Practice Problems

Basic Facts About Dispersion

Vocabulary

Quiz 3

Summary