The standard deviation for the sampling distribution of the mean
(standard error) is given by SD/sq of n, so if the variance = 100, the
SD is (the square root of that) 10.  10/2 (the square-root of 4) gives
the standard error of 5, as you've done.  I agree that's right.

The mean of the sampling distribution equals mu, the population mean
(in this case, 100), by the Central Limit Theorum.  That is, if I
sample repeatedly from any population and compute means for each of my
same-sized samples, the average of those averages will be the
population mean, provided I have enough samples.  So,

SEM = 5      (by computation in accord with definition)
Mean = 100     (by the CLT)

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!STAT IS LIFE!!!!!!!!!!!!!!!!!!!!!!!!!!!



On 9 Mar 2002 08:17:01 -0800, [EMAIL PROTECTED] (Green Bay Blows)
wrote:

>Can anyone straighten me out??
>
>Suppose a random sample of "n" measurements is selected from a
>population with mean u=100 and variance =100.  For "n=4" give the mean
>and standard deviation of the sampling distribution of the sample mean
>(x-bar).
>
>I can figure out the standard deviation, sigma/sq root of n  how does
>one arrive at the "mean"??
>
>For this problem, the standard deviation of the sampling distribution
>would be 10/sq root of 4 or 10/2 = 5.  Anyone agree??

.
.
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