If a certain sample of data has a mean of 20.0 and a standar
If a certain sample of data has a mean of 20.0 and a standard deviation of 3.0,which of the following values is more than
2.5 standard deviations from the mean?
A.12
B.13.5
C.17
D.23.5
E.26.5
大哥,大姐们不是用翻译软件翻译下就OK啊?给下怎么算的~