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NO.PZ2016062402000019 问题如下 A population ha known meof 1,000. Suppose 1,600 samples are ranmly awn (with replacement) from this population. The meof the observesamples is 998.7, anthe stanrviation of the observesamples is 100. Whis the stanrerror of the sample mean? A.0.025 B.0.25 C.2.5 25 This is σt\frac\sigma{\sqrt t}tσ, or1001600\frac{100}{\sqrt{1600}}1600100 =10040\frac{100}{40}40100 = 2.5. Other numbers are irrelevant. 每次随机抽取1600个样本，每次抽取都有一个均值, 所有均值 的 均值就是998.7对吧？然后这个stanrviation of the observesample是指什么？还是说998.7和100只是其中一次抽取的均值和s
麻烦老师辨析两个概念stanrerror of sample mean和stanrviation of observesample. stanrerror sample mean指的是不是抽取n次sample，每一次的sample mean的方差？
老师请问什么是stanrerror of sample mean？和stanrerror of sample 是等同吗？
这个怎么算也应该等于25啊！
