Describe Your Data

From the book, Chapters 3 and 4. Quartiles here use the book’s method: the median of each half, leaving out the middle value when there’s an odd count. Spreadsheets use slightly different recipes, so with small lists their quartiles can differ a little. Outliers are values more than 1.5 IQRs beyond a quartile: a reason to look, not a verdict. Ben’s eleven commutes (the example loaded) give Q1 18, median 25, Q3 34.