Explanation : The first quintile is the 20th percentile and the third quintile is the 60th
percentile. The first decile is the 10th percentile, the first quartile is the
25th percentile, and the median is the 50th percentile. While it is possible
that these various percentiles or some subsets of them might be equal
(for example the10th percentile possibly could be equal to the 20th
percentile), in general the order from smallest to largest would be: first
decile, first quintile, first quartile, median.