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Standard Error Calculations for Population

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A population has a standard deviation of o=20, how large a sample is necessary to have a standard error that is:
Less than or equal to 5 points?
n>______
Less than or equal to 2 points?
n>______
Less than or equal to 1 point?
n>______

If I have a sample of n=25 scores, what is the value of the population standard deviation necessary to produce each of the following standard error values?

oM=10 points
o=_____

oM= 5 points
o=______

oM= 2 points
o=_____

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Solution Preview

SE = o/sqrt(n)
n = (o/SE)^2

Less than or equal to 5 points?
SE =< 5
20/sqrt(n) =< 5
n ...

Solution Summary

Estimation of error and corresponding sample size.

$2.19
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