# Joint

• ### Joke: The Knee

A joke to start a discussion on joint probability distributions.  The joke was written in 2018 by Larry Lesser from The University of Texas at El Paso.

• ### Joke: A Marginal Joke

A joke to be used in describing how a marginal density is computed from a joint density.  The joke was written in 2017 by Larry Lesser (The University of Texas at El Paso) and Dennis Pearl (Penn State University).

• ### Concepts of Confidence Intervals

This PowerPoint presentation dicusses general concepts of confidence intervals and interprets confidence intervals for a mean, difference in two means, and the relative risk. The original presenation is available for download.
• ### A Visualization Tool for One and Two-Way Analysis of Variance Applet

This Java applet helps students visualize features and factors of one and two-way ANOVA tables together with representational models and model parameters.
• ### A Visualization Tool for One and Two-Way Analysis of Variance Article

This is an article published in the Journal of Statistics Education describing the ANOVA Visualization Tool and how it can be used in class.
• ### Exponential Probabilities

The applet in this section allows you see how probabilities are determined from the exponential distribution. The user determines the mean of the distribution and the limits of probability. Three different probability expressions are available. Click "Calculate" to see the pdf and the cdf. The probability is highlighted in green on the pdf. This page was formerly located at http://www.stat.vt.edu/~sundar/java/applets/ExpDensity.html
• ### Normal Distribution

The applets in this section allow users to see how probabilities and quantiles are determined from a Normal distribution. For calculating probabilities, set the mean, variance, and limits; for calculating quantiles, set the mean, variance, and probability. Users can choose from three different probability expressions. Variance is restricted to numbers between 0.1 and 10, inclusive. To select between the different applets you can click on Statistical Theory, Normal Distribution and then the Main Page. At the bottom of this page you can make your applet selection. This page was formerly located at http://www.stat.vt.edu/~sundar/java/applets/
• ### Data+Applet: Restriction of Range

This applet shows how the correlation between two variables is affected by the range of the variable plotted on the X-axis.
• ### DAU StatRefresher: Distributions

This tutorial on Distributions helps students understand the basic concept of probability distributions, recognize and use Binomial, Normal, Poisson, and Uniform Distributions, and solve exercise problems using probability distributions.
• ### Video: Against All Odds: 18. Introduction to Probability

In this free online video program, "students will learn the distinction between deterministic phenomena and random sampling. This program introduces the concepts of sample space, events, and outcomes, and demonstrates how to use them to create a probability model. A discussion of statistician Persi Diaconis's work with probability theory covers many of the central ideas about randomness and probability."