Video

Introduction to Chapter 3
Neil introduces Chapter 3.

Unbiased Versus Biased
Here is one set of data and both the biased and unbiased estimates for the standard deviation computed.

Computing Measures of Variability
View this Video to see how to compute the standard deviation and the variance using SPSS

Chapter Summary
Super cute reflections on learning statistics.

Problem 7
Watch for the solution to this Time to Practice question.

Problem 11
Watch for the solution to this Time to Practice question.

Web

More on Measures of Dispersion
Here's a more extensive treatment of measures of dispersion and how they are used.