3.1. Random variables3.2. Mean, median, and mode3.3. Variance3.4. Two important probability density functions3.5. Functions of a random variable3.6. Joint probabilities3.7. Bayesian inference3.8. Joint probability density functions3.9. Covariance3.10. Multivariate distributions3.11. The multivariate Normal distributions3.12. Linear functions of multivariate data