当我们可以抽取无限多个样本时,分布将会是一个完美的钟形,均值是精确的 1.22 毫米,跟总体均值一样。我们把这种分布称为样本均值的抽样分布(sampling distribution of the sample mean),它是这样一种分布:你从总体中无限抽取样本,计算所有样本的均值。 目前为止,你应当意识到,在实际的研究中,我们不可能从某个总体中...
According to the central limit theorem, a sampling distribution of the sample mean will be approximately normal only if the: A: sample size n is large B:variance of the underlying distribution is known C:population mean of the underlying distribution is known 相关知识点: 试题来源: 解析 A ...
mean v.[T] 1.(词语等)表示...的意思,作...解释 2. 意指,意谓 3. 意味着,即是 4. 意欲,打算;怀有 5. 预定;注定;指定 6. 引起,造成 v.[I] 1. 怀 distribution n. 1.分发,分配 2.散布,分布 3.分配;分布 4.(商品)运销,经销,分销 5.按比例分配;分配法;分发方式 6.分配物,配给物;分...
A. normally distributed with mean m and variance s 2 B. normally distributed with mean m and variance s 2 . C. distributed as a t distribution with variance 1. D. normally distributed with mean 0 and variance 1 E. None of the above相关...
proportion=比例 sampling distribution of the sample mean 样本均值抽样分布 样本均值的抽样分布即所有样本均值的可能取值形成的概率分布。例如，某高校大一年级参加英语四级考试的人数为6000人，为了研究这6000人的平均考分，欲从中随机抽取500人组成样本进行观察。若逐一抽取全部可能样本，并计算出每个样本的...
7.3 The Sampling Distribution of the Sample Mean population:1000;Scale are normally distributed with mean 100 and standard deviation 16 sample:4;可以得到样本均值的分布图如下: 与通过公式计算得到的mean 和 标准差一致:μx¯ = μ = 100 and σx¯ = σ/√n = 16/√4 = 8; ...
The sampling distribution of the sample mean is close to the normal distribution(A)only if both the original population has a normal distribution and n is large.(B) if the standard deviation of the original population is known.(C) if n is large, no matter what the distribution of the ...
Given a population described by any probability distribution (normal or non-normal) with finite variance, the central limit theorem states that the sampling distribution of the sample mean will be approximately normal, with the mean approximately equal to the population mean, when the sample size ...
用样本估计总体是有难度的,即使样本数非常少(population为1000samples为50)Introducing the sampling distribution of the sample mean with an example that isboth realistic and concrete is diffificult because even for moderately large populationsthe number of possible samples is enormous, thus prohibiting an ...
X Distribution of Sample Mean • Because the sample mean is a random variable – The sample mean has a probability distribution – We can obtain the center and spread of the probability distribution of the sample mean • This is called the distribution of the sample mean • Because the ...