SOLUTION: So we have a normal distribution of test scores. Mean score is 120; std deviation is 20. What is the z-value of a test score of 160?? What is the probability of selectin

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Question 155365: So we have a normal distribution of test scores. Mean score is 120; std deviation is 20.
What is the z-value of a test score of 160??

What is the probability of selecting a test score from the group.... a test score between 120 and 160??


Answer by stanbon(48568) About Me  (Show Source):
You can put this solution on YOUR website!
So we have a normal distribution of test scores.
Mean score is 120; std deviation is 20.
What is the z-value of a test score of 160??
z(160) = (160-120)/20 = 2
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What is the probability of selecting a test score from the group.... a test score between 120 and 160??
z(120) = (120-120)/20 = 0
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P(120 < x < 160) = P(0 < z < 2) = 0.4773
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Cheers,
Stan H.