Click on the following links. Please note these will open in a new window.

Video:
Variability
Description: This video explains the concept of variability and homogeneity of variance using a group of dancers.

Concept of Standard Deviation
Description: This video explains the concept of standard deviation.

Calculation of Standard Deviation
Description: This video explains how to calculate standard deviation in a clear and concise manner.

Sample Variance Formula
Description: This video explains why the variance (and standard deviation) calculations differ for samples and populations.