COMM 293 Lecture Notes - Lecture 7: Interquartile Range, Count Data, Box Plot
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Comm 291 summary (by yi liu: data, types of data, categorical data (discrete, or count data, quantitative data (measurement, continuous, or interval) identi er variables, displaying and describing categorical data: Frequency table: bar chart: cumulative frequency table, contingency table: rows by columns; for one variable. Simpson"s paradox: for comparable data: displaying and describing quantitative data: Stem-and-leaf plot (stem plot: histogram, time series plot, box plot, dot plot, numerical methods of describing data, centre: mean, median, mode. Spread: range = max - min, var (s2) & standard deviation (s): s = Percentiles: min, q1, median, q3, max: the interquartile range: iqr = q3 - q1, outer fence: between q1 - 3 iqr and q3 + 3 iqr. Inner fence: between q1 - 1. 5 iqr and q3 + 1. 5 iqr: distribution: Skewed to right (long right-hand tail): mean > median. Skewed to left (long left-hand tail): median > mean: z-score.
