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In words, define the random variables X andX¯.

Short Answer

Expert verified

The sample mean, x¯ is the point estimate for the population mean μ.

Step by step solution

01

Given Information 

The random variables areXandX¯.

02

Explanation 

The sample mean, x¯is the point estimate for the population mean μ.

Suppose that X1,X2,…,Xn, is a random sample from a normal distribution with unknown mean μ, than test statistic

X¯=X1+X2+⋯+Xnn,

is normally distributed with mean μand variance localid="1648836325806" σ2/n.

03

Explanation

It is often necessary to construct confidence intervals on a population proportion. For example, suppose that a random sample of size n has been taken from a large (possibly infinite) population and that X(≤n) observations in this sample belong to a class of interest. Then

P¯=Xn

is a point estimator of the proportion of the population p that belongs to this class.

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