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leozhenlin · 2020年09月29日

问一道题:NO.PZ2015120604000119

问题如下:

Which of the following statements about the sampling distribution of a sample mean is correct?

选项:

A.

The sampling distribution is the probability distribution including all datas that population including.

B.

The sampling distribution is the probability distribution including all possible sample means calculated from  samples whose size is different.

C.

The sampling distribution is the probability distribution including possible sample means calculated from samples whose size is the same.

解释:

C is correct.

Assume a population includes 500 members. If we select 50 menbers ten times, than distribution of ten sample means form an sampling distribution. .

想问下B和C的区别,这个all改变了什么含义,因为选项的意思我读不太透彻,虽然选对了

1 个答案

星星_品职助教 · 2020年09月29日

同学你好,

B选项主要差在后面的“whose size is different”。这道题问的是sample mean的抽样分布。如果抽出来的每个样本的样本容量(sample size,也就是n)是不同的,那么比较不同sample size所计算出来的mean根本没有意义。所以不能选择B,C选项的说法是正确的。

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NO.PZ2015120604000119 问题如下 Whiof the following statements about the sampling stribution of a sample meis correct? A.The sampling stribution is the probability stribution inclung all tthpopulation inclung. B.The sampling stribution is the probability stribution inclung all possible sample means calculatefrom samples whose size is fferent. C.The sampling stribution is the probability stribution inclung all possible sample means calculatefrom samples whose size is the same. C is correct.Assume a population inclus 500 members. If we sele50 menbers ten times, thstribution of ten sample means form sampling stribution. 样本均值的抽样分布是所有的相同size的样本均值形成的分布,即μ的概率分布。样本均值的抽样分布在形状上是对称的。随着样本量n的增大,不论原来的总体是否服从正态分布,样本均值的抽样分布都将趋于正态分布,其分布的数学期望为总体均值μ,方差为总体方差的1/n。这就是中心极限定理(centrlimit theorem) 为什么每个样本量是一样的?

2023-02-22 23:49 1 · 回答

为什么每个样本容量是一样的呢?我理解这道题问的是每个样本均值的分布的特点,那有可能是随机抽样,不一定是分层抽样吧?

2020-02-27 13:21 1 · 回答

    提问老师,这题的不太看的明白,麻烦您一下和为何选C。谢谢您

2018-10-26 17:22 1 · 回答

    这道题说的是什么意思?

2017-04-01 16:58 1 · 回答