Discover what quartiles are in statistics, how to calculate them, and see examples to help you interpret data more ...

Quartiles are the values that divide a data set into quarters: Put the values in order Divide the list into four equal parts The Quartiles are at the divisions The interquartile range shows the ...

Semi-interquartile range The semi-interquartile range is half of the difference between the upper quartile and the lower quartile. In the previous example, the quartiles were Q 1 = 4 and Q 3 = 11.

Tokishige Hojo, Karl Pearson, Distribution of the Median, Quartiles and Interquartile Distance in Samples From a Normal Population, Biometrika, Vol. 23, No. 3/4 (Dec., 1931), pp. 315-363 ...