• ### Numerical Summaries

This site gives a definition and an example of numerical summaries. Topics include mean, median, quantiles, variance, and standard deviation.
• ### Conditional Probability

This site gives an explanation, a definition and an example of conditional probability. Topics include the probabilities of intersections of events and Bayes' formula.
• ### Mean and Variance of Random Variables

This site gives an explanation, a definition and an example of mean and variance of random variables. Definitions and properties are also included.
• ### Random variables

This site gives an explanation, a definition and an example of random variables including discrete and continuous. It also defines a density curve.
• ### The Binomial Distribution

This site gives an explanation of, an example of, and a definition for binomial distributions including counts, proportions, and normal approximation.
• ### Sample Means

This site gives an explanation of, a definition for and an example of sample means. Topics include mean, variance, distribution, and the Central Limit Theorem.
• ### Confidence Intervals

This site gives an explanation of, a definition for and an example of confidence intervals. It covers topics including inference about population mean and z and t critical values.
• ### Sampling Distribution Generator for Sample Mean Differences

This page generates a graph of the sampling distribution of the difference between two means and displays the probabilities associated with that distribution. Users enter the population standard deviation and the sample sizes, Na and Nb. The applet also calculates the standard error of the sample mean difference.

• ### Sampling Distribution Generator for r (Correlation Coefficient)

This page generates a graph of the sampling distribution of r, the Pearson correlation coefficient. Upon opening, the applet prompts for sample size greater than 6. The applet also displays the probabilities associated with the distribution.

• ### t-Distribution Generator

Generate a graphic and numerical display of the properties of the t-distribution for values of df between 4 and 200, inclusive.