How to Measure Variability in Quantitative Data

Here is the video version of Lesson 4 from Stat Trek's free online tutorial covering the complete curriculum for Advanced Placement (AP) Statistics.

About This Video

This video lesson shows how to compute four measures of variability in statistics: the range, interquartile range (IQR), variance, and standard deviation. Step-by-step sample problems illustrate computations.

A written version of the material covered in this video is available at https://stattrek.com/descriptive-statistics/variability.

About Stat Trek's Video Series

A little history: About two decades ago, Stat Trek produced a free online tutorial covering the complete curriculum for AP Statistics. The tutorial, which can be found at https://stattrek.com/tutorials/ap-statistics-tutorial, was to designed to help students prepare for and pass the AP Statistics exam. Consisting of 69 easy-to-understand written lessons, the tutorial was very well-received.

Of course, there is always room for improvement. With that in mind, some students suggested supplementing the written lessons with video instruction. The Stat Trek video series is our response to that suggestion. So far, we've produced 45 video lessons, one video lesson for each of the first 45 written lessons from Stat Trek's' AP Statistics Tutorial.

The work continues. We're adding videos little by little. Eventually, we intend to have a video for each of the 69 written lessons from the tutorial.