<PRE><B>Question 411595</B>
A set of 50 data values has a mean of 15 and a variance of 36. Find the standard score of a data value = 20
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How far is 20 from the mean?
20-15 = 5
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How many standard deviations is that?
5/sqrt(36) = 5/6 = 0.8333
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That is the z-score for 20. 
That is the standard score.
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In general, the z score for a data value
is z(x) = (x-u)/std
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Cheers,
Stan H.
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