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标题: 请教一级数量问题 [打印本页]

作者: busterbluth    时间: 2013-9-14 02:02     标题: 请教一级数量问题

请教老师mock83-31
which is least likely to increase the reliability of parameter estimates?
A. increase the sample size
B. use of point estimates rather than confidence intervals
C. use of t-distribution rather than normal distribution to establish confidence
答案选B,关于C选项,是不是t分布相比较正态分布而言,分布分散,所以估计没有正态分布准确,那么C也应该选是吗?请老师解答,谢谢!
作者: apf陈老师    时间: 2013-9-14 02:18

一般我们用normal distribution 来确定置信区间的前提是我们必须确定这个整体或样本的分布式正态分布。
而t-distribution的运用更广泛。
所以,a consevation approach to confidence intervals relies on the t-distribution rather than the normal distribution, and use of the t-distribution will increase the reliability of the confidence interval.




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