Subject & Study Guides: DIY Maths: Range, variation and standard deviation

RANGE, VARIATION AND STANDARD DEVIATION

In this module, you can study the basic statistical measures of dispersion: range, variance and standard deviation.

Variation and standard deviation both show how spread out the data set is.

A data set of any size can have a large or a small standard deviation.

Study range
This page from mathgoodies.com explains how to find the range of a data set. After you read through the examples, you can try a few problems of your own.
Study variance and standard deviation
Mathsisfun.com does a good job of explaining how to find variance and standard deviation. At the end of this page, you will find a quiz to test your knowledge. For a more advanced discussion, see www.onlinemathlearning.com/variance.html.
Quiz yourself on standard deviation
This five-question quiz from usablestats.com checks your understanding of the concept of standard deviation.
Quiz yourself on standard deviation by building your own quiz
Make a list of numbers (a data set) and use this online calculator to find the standard deviation of the set. Compare the calculator's answer to your own worked-out answer to see if you have it right.