This document provides an overview and lecture notes for chapters 3-5 of an introductory statistics course. It discusses preparing preliminary analyses of categorical and quantitative variables through graphs and descriptive statistics. For categorical variables, it describes frequency tables, contingency tables, bar charts, and pie charts. For quantitative variables, it introduces histograms, boxplots, dot plots, and stem-and-leaf displays. It emphasizes using graphs to understand the shape, center, and spread of variable distributions. The document also briefly discusses Simpson's paradox and performing preliminary analyses by hand.