Quartile
One of the four divisions of observations which have been grouped into four equal-sized sets based on theirRank. The quartile including the top Ranked members iscalled the first quartile and denoted 
. The other quartiles are similarly denoted 
, 
, and 
. For
data points with of the form 
(for 
, 1, ...), the Hinges are identical to the firstand third quartiles.
- Quasiperiodic Motion
- Quasirandom Sequence
- Quasiregular Polyhedron
- Quasirhombicosidodecahedron
- Quasirhombicuboctahedron
- Quasisimple Group
- Quasithin Theorem
- Quasitruncated Cuboctahedron
- Quasitruncated Dodecadocahedron
- Quasitruncated Dodecahedron
- Quasitruncated Great Stellated Dodecahedron
- Quasitruncated Hexahedron
- Quasitruncated Small Stellated Dodecahedron
- Quasi-Unipotent Group
- Quasi-Unipotent Problem
- Quaternary
- Quaternary Tree
- Quaternion
- Quattuordecillion
- Queens Problem
- Queue
- Queuing Theory
- Quicksort
- Quillen-Lichtenbaum Conjecture
- Quincunx