# Data Presentation

• ### Log-likelihood ratio

This site offers an involved definition of the likelihood ratio test with examples and formulas.
• ### The Beta Distribution

This applet allows the user to adjust a (1st shape) and b (2nd shape) parmaters of the Beta distribution with a slider or manual input. The applet allows the user to fix the x and or y axes. The user immediately sees how this affects the the shape of the graph as well as the variance and the expected value. This page was formerly located at http://www.stat.vt.edu/~sundar/java/applets/BetaDensityApplet.html
• ### Simple Linear Regression

This tutorial on Simple Linear Regression includes its definition, assumptions, and characteristics as well as related statistics and hypothesis test procedures. One section instructs users to perform simple linear regression in the WINKS software, but those without the software can still use the tutorial. An exercise is given at the end that can be done with any statistical software package.
• ### Chi Square Tests

The eighth chapter of an online Introduction to Biostatistics course. Lecture notes are provided. Additionally, links for additional reading and exercises with solutions are provided.
• ### Correlation

This page gives a description of correlation, Pearson's r, Spearman's rho. There are some scatterplots illustrating the different values of r.

• ### Case Studies in Process Modeling (Engineering Statistics Handbook)

The online "Engineering Statistics Handbook" provides a section (4.6 Case Studies in Process Modeling) using detailed realistic examples from physical science and engineering applications. Examples in Load Cell Calibration, Alaska Pipeline Ultrasonic Calibration, Ultrasonic Reference Block Study, and Thermal Expansion of Copper Case Study are presented in a step-by-step manner.
• ### RVLS Case Studies

This site provides case studies which cover subject areas including: analysis of variance, boxplots, confidence intervals, contrast among means, correlated t-test, correlation, histograms, independent groups t-test, regression, repeated measures ANOVA, and t-tests.
• ### Variance and standard deviation

This source defines and explains variance and standard deviation.
• ### Basic Sample Stats Calculator

The page calculates summary statistics for any dataset. Users will be prompted for sample size when opening this page. The calculator returns mean, sum of X, sum of X^2, variance, standard deviation, and standard error. Key word: Descriptive statistics.

• ### Analysis Tool: Basic Multiple Regression

This page will perform basic multiple regression analysis for the case where there are several independent predictor variables, X1, X2, etc., and one dependent or criterion variable, Y. Requires import of data from a spreadsheet.