(statistics) Any of the three points that divide an ordered distribution into four parts, each containing a quarter of the population. / (statistics) Any one of the four groups so divided.

plural of quartile

Divided into quartiles

The quartile (designated Q₁) having the lowest value; it cuts off the lowest 25% of data.

(mathematics) The median of the upper or highest half of a data set, especially of a sample, population, or probability distribution.

plural of upper quartile

plural of lower quartile