McGraw Hill
Glencoe: Self Check Quizzes 1 Median, Mode and Range
Use Glencoe's randomly generated self-checking quiz to test your knowledge of median, mode and range. Each question has a "Hint" link to help. Choose the correct answer for each problem. At the bottom of the page click the "Check It"...
Other
Dispersion
This site discusses the range, average deviation, variance, and standard deviation, as well as their relation to dispersion.