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The five-number summary is a descriptive statistic that provides information about a set of observations. It consists of the five most important sample percentiles: # the sample minimum (smallest observation) # the lower quartile or ''first quartile'' # the median (middle value) # the upper quartile or ''third quartile'' # the sample maximum (largest observation) In order for these statistics to exist the observations must be from a univariate variable that can be measured on an ordinal, interval or ratio scale. ==Use and representation== The five-number summary provides a concise summary of the distribution of the observations. Reporting five numbers avoids the need to decide on the most appropriate summary statistic. The five-number summary gives information about the location (from the median), spread (from the quartiles) and range (from the sample minimum and maximum) of the observations. Since it reports order statistics (rather than, say, the mean) the five-number summary is appropriate for ordinal measurements, as well as interval and ratio measurements. It is possible to quickly compare several sets of observations by comparing their five-number summaries, which can be represented graphically using a boxplot. In addition to the points themselves, many L-estimators can be computed from the five-number summary, including interquartile range, midhinge, range, mid-range, and trimean. The five-number summary is sometimes represented as in the following table: 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Five-number summary」の詳細全文を読む スポンサード リンク
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