SOLUTION: IQ scores have a normal distribution with a mean of 100 and a standard deviation of 15. Out of a student body of 1800 students, how many would you expect to have an IQ above 120

Question 114746: IQ scores have a normal distribution with a mean of 100 and a standard deviation of 15. Out of a student body of 1800 students, how many would you expect to have an IQ above 120?

Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
IQ scores have a normal distribution with a mean of 100 and a standard deviation of 15. Out of a student body of 1800 students, how many would you expect to have an IQ above 120?
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Find the z-score for 120
z(120)= (120-100)/15
z(120) = 1.333333....
Prob(z>1.3333...) = 0.09121182...
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Answer: 0.09121192..*1800 = 164.18..
Rounding down get 164 students.
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Cheers,
Stan H.
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