13.1 Describing Raw Data13.1.1 Numeric Variables13.1.2 Categorical Variables13.1.3 Univariate and Multivariate Data13.1.4 Parameter or Statistic?Exercise 13.113.2 Summary Statistics13.2.1 Centrality: Mean, Median, Mode13.2.2 Counts, Percentages, and ProportionsExercise 13.213.2.3 Quantiles, Percentiles, and the Five-Number Summary13.2.4 Spread: Variance, Standard Deviation, and the Interquartile RangeExercise 13.313.2.5 Covariance and Correlation13.2.6 OutliersExercise 13.4