SOLUTION: for a normal distribution problem, I know the formula to find a z-score includes the known standard deviation---but how do I solve for finding a standard deviation if my only known

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Question 993636: for a normal distribution problem, I know the formula to find a z-score includes the known standard deviation---but how do I solve for finding a standard deviation if my only known numbers are the z-score and the number it corresponds to? I.E. A score that is 12 points above the mean corresponds to a z-score of 2. What is the standard deviation? I took 12/2=6. solving 6 as my standard deviation but not sure if correct formula

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A score that is 12 points above the mean corresponds to a z-score of 2. What is the standard deviation? I took 12/2=6. solving 6 as my standard deviation but not sure if correct formula
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You are correct.
If a number has a z-score of 2 that means the number is
2 standard deviations to the right of the mean.
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If the mean is zero, and 12 is 2 std to the right,
the std must be 12/2 = 6.
Cheers,
Stan H.
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