McGraw Hill
Glencoe: Using Graphs to Understand Data Quiz
This is a quiz with five quick questions to check your knowledge of how to use graphs to understand data. It is self-checking.
University of Illinois
University of Illinois: Rollin' Rollin' Rollin'
This resource is the beginning of a series of pages that demonstrates the diffference between the mean and median of a group of numbers. Uses bar graphs to display the data.