From the Introduction:

Richard Lowry wrote:Welcome to "Concepts and Applications of Inferential Statistics", which is a free, full-length, and occasionally interactive statistics textbook. It is a companion site of "VassarStats: Web Site for Statistical Computation". The materials on this site may be freely used for any non-commercial educational purpose.

Table of Contents:

Chapter 1. Principles of Measurement
Chapter 2. Distributions
Chapter 3. Introduction to Correlation & Regression
Chapter 4. A First Glance at the Question of Statistical Significance
Chapter 5. Basic Concepts of Probability
Chapter 6. Introduction to Probability Sampling Distributions
Chapter 7. Tests of Statistical Significance: Three Overarching Concepts
Chapter 8 Chi-Square Procedures for the Analysis of Categorical Frequency Data.
Chapter 9. Introduction to Procedures Involving Sample Means
Chapter 10. t-Procedures for Estimating the Mean of a Population
Chapter 11. t-Test for Two Independent Samples
Chapter 12. t-Test for Two Correlated Samples
Chapter 13. Conceptual Introduction to the Analysis of Variance
Chapter 14. One-Way Analysis of Variance for Independent Samples
Chapter 15. One-Way Analysis of Variance for Correlated Samples
Chapter 16. Two-Way Analysis of Variance for Independent Samples
Chapter 17. One-Way Analysis of Covariance for Independent Samples