![](https://static.youtibao.com/asksite/comm/h5/images/m_q_title.png)
[单选题]
抽取一个容量为50的样本,其均值为10,标准差为5,则总体均值95%的置信区间为()
A.{8.60,11.40]
B.[8.04,11.96]
C.[7.65,12.35]
D.[6.90,13.10]
![](https://static.youtibao.com/asksite/comm/h5/images/m_q_a.png)
A、{8.60,11.40]
解析:总体方差未知使用样本方差S2Π-1一25作为总体方差的估计值标准误的公式是S`X=SN-1/√N-1得标准误是0714因为样本容量较大(50)即可以利用Z值进行估计Z005/2是196则总体均值95%的置信区间是[10-196×071410+196×0714]可得[8601140]
![](https://static.youtibao.com/asksite/comm/h5/images/solist_ts.png)