Position of an element in a ordered statistical series subdivided into five intervals with the same frequency.
Example
If we say that a student is in the 3rd quintile rank of his or her group, this means that 20% of the students are in the same rank, 40% of students are in the 1st and 2nd quintile ranks, and 40% of the students are in the 4th and 5th quintile ranks of his or her group..