Eric Lund <[EMAIL PROTECTED]> wrote in sci.stat.edu:
>In Indiana, the school accountability legislation calls for locally
>produced assesments to be used. An assessment is to be given to about
>1600 students in the high school in which I teach. This assessment
>will be given each September and May starting with the 2003-2004
>school year. How large of a sample must be drawn from this population
>in order to approximate the mean score for all of the students?
The answer depends on three things: the population standard
deviation, the level of confidence you want in your estimate, and
the amount of spread you're willing to tolerate in the estimate. For
instance, if you can accept an estimate with a spread of plus or
minus 80 points at 95% confidence, you can take a smaller sample
than if you need a spread of no more than 20 points at 95%
confidence.
However...
If I understand your scenario, you don't really need to do any
sampling. You'll have the score of every student who took the test,
so you can compute the population mean score exactly.
--
Stan Brown, Oak Road Systems, Cortland County, New York, USA
http://OakRoadSystems.com
"Life! Don't talk to _me_ about life!"
.
.
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