SOLUTION: If IQ tests have a mean of 100 and standard deviation of 15, what proportion of the population have
a) an IQ greater than 120, and
b) an IQ less than 70?
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-> SOLUTION: If IQ tests have a mean of 100 and standard deviation of 15, what proportion of the population have
a) an IQ greater than 120, and
b) an IQ less than 70?
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Question 505144: If IQ tests have a mean of 100 and standard deviation of 15, what proportion of the population have
a) an IQ greater than 120, and
b) an IQ less than 70? Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! If IQ tests have a mean of 100 and standard deviation of 15, what proportion of the population have
a) an IQ greater than 120,
z(120) = (120-100)/15 = 20/15 = 4/3
Prop above 120 = P(z > 4/3) = 0.0912
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and
b) an IQ less than 70?
z(70) = (70-100)/15 = -2
Prop below 70 = P(z < -2) = 0.0228
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Cheers,
Stan H.
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