▁the ▁mid - range ▁are ▁often ▁used ▁in ▁addition ▁to ▁the ▁mean ▁as ▁estimates ▁of ▁central ▁t endency ▁in ▁descript ive ▁statistics . ▁These ▁can ▁all ▁be ▁seen ▁as ▁minim izing ▁variation ▁by ▁some ▁measure ; ▁see ▁. ▁ ▁Mode ▁ ▁The ▁most ▁frequently ▁occurr ing ▁number ▁in ▁a ▁list ▁is ▁called ▁the ▁mode . ▁For ▁example , ▁the ▁mode ▁of ▁the ▁list ▁( 1 , ▁ 2 , ▁ 2 , ▁ 3 , ▁ 3 , ▁ 3 , ▁ 4 ) ▁is ▁ 3 . ▁It ▁may ▁happen ▁that ▁there ▁are ▁two ▁or ▁more ▁numbers ▁which ▁occur ▁equally ▁often ▁and ▁more ▁often ▁than ▁any ▁other ▁number . ▁In ▁this ▁case ▁there ▁is ▁no ▁agreed ▁definition ▁of ▁mode . ▁Some ▁authors ▁say ▁they ▁are ▁all ▁modes ▁and ▁some ▁say ▁there ▁is ▁no ▁mode . ▁ ▁Med ian ▁ ▁The ▁median ▁is ▁the ▁middle ▁number ▁of ▁the ▁group ▁when ▁they ▁are ▁ranked ▁in ▁order . ▁( If ▁there ▁are ▁an ▁even ▁number ▁of ▁numbers , ▁the ▁mean ▁of ▁the ▁middle ▁two ▁is ▁taken .) ▁ ▁Thus ▁to ▁find ▁the ▁median , ▁order ▁the ▁list ▁according ▁to ▁its ▁elements ' ▁magnitude ▁and ▁then ▁repeatedly ▁remove ▁the ▁pair ▁consisting ▁of ▁the ▁highest ▁and ▁lowest ▁values ▁until ▁either ▁one ▁or ▁two ▁values ▁are ▁left . ▁If ▁exactly ▁one ▁value ▁is ▁left , ▁it ▁is ▁the ▁median ; ▁if ▁two ▁values , ▁the ▁median ▁is ▁the ▁arithmetic ▁mean ▁of ▁these ▁two . ▁This ▁method ▁takes ▁the ▁list ▁ 1 , ▁ 7 , ▁ 3 ,