# Multivariate Categorical Relationships

• ### Video: Against All Odds: 17. Samples and Surveys

This free online video program "shows how to improve the accuracy of a survey by using stratified random sampling and how to avoid sampling errors such as bias. While surveys are becoming increasingly important tools in shaping public policy, a 1936 Gallup poll provides a striking illustration of the perils of undercoverage."
• ### Project #2: Probability Summary

This assignment has students investigate whether the risk of having a child with a low birth weight is higher when the mother drinks and smokes during pregnancy. The data set represents a random sample of 1450 births from the state of North Carolina.
• ### JMP Tutorials

This site has Youtube video tutorials and screen capture tutorials about how to make graphical displays and perform statistical tests using JMP.
• ### Against All Odds: 2. Picturing Distributions

With this free online video program, "students will see how key characteristics in the distribution of a histogram - shape, center, and spread - help professionals make decisions in such diverse fields as meteorology, television programming, health care, and air traffic control. Through a discussion of the advantages of back-to-back stem plots, this program also emphasizes the importance of seeking explanations for gaps and outliers in small data sets." This individual video is accessed by scrolling down to the "Individual Program Descriptions - 2. Picturing Distributions" and click the "VOD" icon at the top-right of the description.
• ### Geometric Models

This online, interactive lesson on geometric models provides examples, exercises, and applets which include Buffon's Problems, Bertrand's Paradox, and Random Triangles.

• ### Probability, Mathematical Statistics, and Stochastic Processes

This online, interactive lesson on finite sampling models provides examples, exercises, and applets that include hypergeometric distribution, multivariate hypergeometric distribution, order statistics, the matching problem, the birthday problem, and the coupon collector problem.

• ### Renewal Processes Apps

This online, interactive lesson on the renewal processes provides examples, exercises, and applets which include renewal equations and renewal limit theorems.

• ### Probability Spaces

This online, interactive lesson on probability spaces provides examples, exercises, and applets that cover conditional probability, independence, and several modes of convergence that are appropriate for random variables. This section also covers probability space, the paradigm of a random experiment and its mathematical model as well as sample spaces, events, random variables, and probability measures.

• ### Markov Chains

This online, interactive lesson on Markov chains provides examples, exercises, and applets that cover recurrence, transience, periodicity, time reversal, as well as invariant and limiting distributions.
• ### Free Statistics Software

This site is a collection of Web-enabled scientific services & applications including Equation Plotter Software, Scientific Forecasting Software, Multiple Regression Software, Descriptive Statistics Software, Statistical Hypothesis Testing Software, Sample Size Software, and XML-RPC PHP client.