Classify data as categorical or quantitative and as discrete or continuous, evaluate sampling methods for undercoverage, convenience or voluntary response, and nonresponse bias, and recognize that random sampling reduces selection bias without eliminating sampling variability. Calculate and interpret the mean, median, mode, range, interquartile range, variance, and standard deviation for lists or frequency tables, and construct and interpret histograms and box plots using distribution, center, spread, skewness, and possible outliers. Construct and interpret scatter plots, describe the direction and strength of linear or nonlinear association while distinguishing correlation from causation, and use lines of best fit to make and evaluate interpolated or extrapolated predictions.