SOLUTION: IQ scores are normally distributed with a mean u=100 and a standard deviation o=15. Based on this distribution, determine A. the percentage IQ scores between 100 and 120. B. t

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Question 84799This question is from textbook Elementary Statistics in social research
: IQ scores are normally distributed with a mean u=100 and a standard deviation o=15.
Based on this distribution, determine
A. the percentage IQ scores between 100 and 120.
B. the probability of selecting a person at random having an IQ between 100 and 120
C. the percentage of IQ scores between 88 and 100.
D. the probability of selecting a person at random having and IQ between 88 and 100.
E. the percentage of IQ scores that 110 or above.
F. the probability of selecting a person at random having an IQ of 110 or above. This question is from textbook Elementary Statistics in social research

Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
IQ scores are normally distributed with a mean u=100 and a standard deviation o=15.
Based on this distribution, determine
A. the percentage IQ scores between 100 and 120.
The z-score of 100 is zero; The z-score of 120 is (120-100)/15 = 1.3333
P(0 ------------------
B. the probability of selecting a person at random having an IQ between 100 and 120
Prob = 0.4088
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C. the percentage of IQ scores between 88 and 100.
z-score of 88 = (88-100)/15 = -0.8
z-score of 100 = 0
P(-0.8 ----------------
D. the probability of selecting a person at random having and IQ between 88 and 100.
Same answer as C.
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E. the percentage of IQ scores that 110 or above.
z-score of 110 is (110-100)/15 = 0.666667
P(z>0.6666667) = 0.2525 = 25.25%
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F. the probability of selecting a person at random having an IQ of 110 or above.
Same as E.
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Cheers,
Stan H.