# Simulation

• ### HyperStat Online: Ch. 8 Confidence Intervals

This resource gives a thorough definition of confidence intervals. It shows the user how to compute a confidence interval and how to interpret them. It goes into detail on how to construct a confidence interval for the difference between means, correlations, and proportions. It also gives a detailed explanation of Pearson's correlation. It also includes exercises for the user.

• ### Confidence Intervals

This resource assists the user in reading, constructing, and understanding confidence intervals.
• ### Stats: Sample Size Determination

This resource provides the user with a formula for obtaining sample sizes of a mean and proportion.
• ### Statistical Significance

This article may help the user understand the concept of statistical significance and the meaning of the numbers produced by The Survey System. This article is presented in two parts. The first part simplifies the concept of statistical significance as much as possible; so that non-technical readers can use the concept to help make decisions based on their data. The second part provides more technical readers with a fuller discussion of the exact meaning of statistical significance numbers.
• ### Significance Level

This resource briefly explains what a significance level is and how they are used in hypothesis testing. It also includes other links related to significance level such as "Type I error" and "significance test".
• ### Interpreting Statistical p-values

This page discusses the understanding of and interpretation of p-values for those who read articles with statistical information.
• ### HyperStat Online: Ch. 11 Power

This site defines power and explains what factors may affect it, such as significance level, sample size and variance.

• ### Confidence Intervals & Hypothesis Testing

This site explains the relationship between hypothesis testing and confidence intervals.
• ### **Introduction to hypothesis testing -- The z-test

This exercise will help the user understand the logic and procedures of hypothesis testing. To make best use of this exercise, the user should know how to use a z table to find probabilities on a normal distribution, and how to calculate the standard error of a mean. Relevant review materials are available from the links provided. The user will need a copy of the hypothesis testing exercise (link is provided), a table for the standardized normal distribution (z), and a calculator. The user will be asked several questions and will be given feedback regarding their answers. Detailed solutions are provided, but users should try to answer the questions on their own before consulting the detailed solutions. The end of the tutorial contains some "thought" questions.
• ### Java Demos for Probability and Statistics

A small collection of applets on the following topics: Introduction to Probability Models, Hypergeometric Distribution, Poisson Distribution, Normal Distribution, Proportions, Confidence Intervals for Means, The Central Limit Theorem, Bivariate Normal Distribution, Linear Regression, Buffon's Needle Problem.