# Probability & Sampling

• ### HotBits

HotBits is a genuine random number generator powered by radioactive decay. Simply click the "Request HotBits" link, and specify how many bytes you would like (up to 2048) and in what form you prefer them. Hexadecimal returns numbers and letters, while C language returns integers. Then click the "Get HotBits" button, and your random numbers will appear on the screen.
• ### Data Collection: Data Sets from Regression Graphics

The datasets in this collection are in text format, but are also compatible with Arc software from "Regression Graphics." Each set has a title, description, and data table. The software is available in the relation link below.
• ### Statistics and Probability Tutorial

This tutorial provides a basic introduction to many topics in statistics and probability. Topics include: Sets and subsets, Statistical experiments, Counting, Basic probability rules, Bayes' theorem, Probability distributions, Discrete vs. Continuous, Binomial, Negative Binomial, Hypergeometric, Multinomial, Poisson, Normal, Sampling theory, Central tendency, Variability, Sampling distributions, t Distribution, Chi-Square Distribution, F Distribution, Estimation problems, Hypothesis testing, Power, Survey sampling, Simple random samples, Stratified samples, Cluster samples, Sample size.
• ### Race and Changing Household Structure

The textbook for this course discusses cross-cultural variations in household structure, as well as changes across time in household structure in the United States. The purpose of this exercise is to examine variations in household structure in the United States according to race and historical period. By the end of the exercise students should have a better appreciation of the fact that household structure in the U.S. is very fluid and that changes over time in household structure have not progressed uniformly for all race groups.
• ### Racing Game with One Die

This applet allows the user to simulate a race where the results are based on the roll of a die. For each outcome of the die, the user chooses which player moves forward. Then that car moves forward the given number of spaces. Users can experiment with the race by determining which player will win more often based on the rules that they specify.

• ### Distribution Calculator Lines

The program DistCalc calculates probabilities and critical values for the most important distributions. The purpose of this program is to show the concept of critical values and the replacement of printed distribution tables. The Distribution Calculator offers calculations for the normal distribution, the t distribution, the chi-square distribution, and the F distribution.

• ### 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."
• ### **Normal Approximation to the Binomial Distribution

This demonstration allows you to view the binomial distribution and the normal approximation to it as a function of the probability of a success on a given trial and the number of trials. It can be used to compute binomial probabilities and normal approximations of those probabilities.
• ### Random Samples

This online, interactive lesson on random samples provides examples, exercises, and applets concerning sample mean, law of large numbers, sample variance, partial sums, central limit theorem, special properties of normal samples, order statistics, and sample covariance and correlation.
• ### Sampling Methods

This site briefly defines several different types of sampling methods, contrasts probability and nonprobability sampling, and discusses target population. Part of a tutorial on questionnaire and survey design.