Khan Academy
Khan Academy: Normal Distributions Review
Normal distributions come up time and time again in statistics. A normal distribution has some interesting properties: it has a bell shape, the mean and median are equal, and 68% of the data falls within 1 standard deviation.
Hofstra University
Hofstra University: Review Exercises Random Variables..
Interactive review problems are offered to practice the concepts of random variables and statistics. Topics covered include, Bernoulli trials, normal and binomial distributions, Chebyshev's rule, and the like.
Shodor Education Foundation
Shodor Interactivate: Stats and Probability Concepts
Many topics on Statistics and Probability are defined and linked here. Click on any of them to move to a more detailed discussion of the term.
University of Glasgow
Statistics Glossary: Stratified Sampling
An online statistics glossary which contains the definition for stratified sampling. Lists reasons for using stratified sampling instead of simple random sampling and gives an example situation in which stratified sampling may be used.
Rice University
Hyper Stat Online Statistics Textbook: Population
A definition of "population" as it refers to statistics.
California State University
Cal State San Bernardino: Intro to Probability Models
The concept of random variables comes to life with this Applet used to roll one, two, six, or nine dice. The user selects the number of rolls to be completed, and the program quickly counts and graphs the results.
Other
Berrie's Statistics Page: Graph of Normal Distribution
Explanation of the Normal Curve and the importance of the normal distribution
Other
Fayetteville State University: Z Scores and Probability
Several paragraphs of explanation and graphs are found here to get across the concept of normal scores, z-scores, and the related probability in a simple fashion. This page is part of a collection from the university on basic statistical...
Stefan Warner and Steven R. Costenoble
Finite Mathematics & Applied Calculus: Normal Distribution Utility
The learning tool calculates the probability of a normal distribution.
Stefan Warner and Steven R. Costenoble
Finite Mathematics & Applied Calculus: Normal Distribution Table
The resource consists of a normal distribution table.
Web Center for Social Research Methods
Research Methods Knowledge Base: Probability Sampling
This site from Cornell University contains great information on random or probability sampling. Definitely a site worth checking out on the subject.
Varsity Tutors
Varsity Tutors: Hotmath: Statistical Questions
Explains what a statistical question is and when and how central tendency and the spread of the data are relevant.
Science Struck
Science Struck: Types of Skewed Distribution With Real Life Examples
Explains what is meant by a skewed distribution, describes the two types, and gives examples.
BBC
Bbc: Standard Deviation
A demonstration of how to find the standard deviation of a set of data. Several examples and a practice test are offered.
University of Georgia
University of Georgia: Inter Math: Sample
This site gives a description of a sample (of a population). The page offers information on various types of sampling. There are links to related terms, everyday examples, more information, and the interactive check point involving...
University of Glasgow
Steps Statistics Glossary: Sampling Distribution
This site provides an overview of sampling distribution and associated terms.
University of Glasgow
Statistics Glossary: Target Population
Go to this site for a brief definition for what the target population of a sample is along with an example problem.
Other
Berrie's Statistics Page: Normal Distribution
Site discusses the normal distribution as well as the mean and variance in the normal distribution. A link is provided for a QuickTime activity to adjust the mean.