The Hong Kong ynemployment rate in the year of 4/2006-3/2007 was as following :
4/2006 7.8
5/2006 8.3
6/2006 8.6
7/2006 8.7
8/2006 8.6
9/2006 8.3
10/2006 8.0
11/2006 7.5
12/2006 7.3
1/2007 7.3
2/2007 7.2
3/2007 7.3
why the standard deviation and the mean is 7.9 and 0.55?
2015-12-26 8:24 am
回答 (1)
2015-12-26 8:55 am
✔ 最佳答案
SolEX=(7.8+8.3+8.6+8.7+8.6+8.3+8.0+7.5+7.3+7.3+7.2+7.3)/12
=(8.7+2*8.6+2*8.3+8.0+7.8+7.5+3*7.3+7.2)/12
=94.9/12
=7.90833
EX^2=(8.7^2+2*8.6^2+2*8.3^2+8.0^2+7.8^2+7.5^2+3*7.3^2+7.2^2)/12
=754.19/12
=62.8491667
VarX=EX^2－(EX)^2=62.8491667－(7.90833)^2=0.307483
√VarX=√0.307483=0.55446
Mean=7.90833
Standard deviation=0.55446
收錄日期: 2021-04-30 19:49:48
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20151226002429AAChTUJ