请教,这题目是啥意思阿...

来源: 于 2009-12-06 11:25:40 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

在准备ＧＭＡＴ考试,看到这题目,根本没看懂题目的意思,请高手帮忙看下:

A researcher computed the mean,the median,and the standard deviation for aset of performance scores. If 5 were to be added to each score,which of these　three statistics would change?

a. the mean only
b . the median only
c.the standard deviation only
d.the mean and the median
e. the mean and the standard deviation