(2002•益陽)數(shù)據(jù)100,80,75,72,70,50的中位數(shù)是 .
【答案】
分析:根據(jù)中位數(shù)的定義求解.這組數(shù)據(jù)按從小到大排列為50,70,72,75,80,100,則中間兩個數(shù)的平均數(shù)為中位數(shù).
解答:解:將這組數(shù)據(jù)按從小到大排列為50,70,72,75,80,100.
由于有偶數(shù)個數(shù),取最中間兩個數(shù)的平均數(shù)即為中位數(shù),則中位數(shù)為
=73.5.
故答案為73.5.
點評:本題考查了中位數(shù)的定義.一組數(shù)據(jù)的中位數(shù)與這組數(shù)據(jù)的排序及數(shù)據(jù)個數(shù)有關,因此求一組數(shù)據(jù)的中位數(shù)時,先將該組數(shù)據(jù)按從小到大(或按從大到。┑捻樞蚺帕校缓蟾鶕(jù)數(shù)據(jù)的個數(shù)確定中位數(shù):當數(shù)據(jù)個數(shù)為奇數(shù)時,則中間的一個數(shù)即為這組數(shù)據(jù)的中位數(shù);當數(shù)據(jù)個數(shù)為偶數(shù)時,則最中間的兩個數(shù)的算術平均數(shù)即為這組數(shù)據(jù)的中位數(shù).