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deviation

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by drgmatIL » Sat Aug 09, 2008 4:25 am
can someone explain me how I answer this type of questions
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by raunekk » Sat Aug 09, 2008 5:05 am
mean=21
SD=6

1 SD below the mean is 21-6=15

2 SD below the mean is 21-2(6)=9

The only number between them in the answer choices is 12..

thus Answer= 12

Let me know if i am wrong.

thx
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by pepeprepa » Sat Aug 09, 2008 5:32 am
Try to practice other standard deviation problems, in general they are not very hard and always deal with the same kind of concepts.
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