SOLUTION: IQ scores have a normal distribution with a mean of 100 and a standard deviation of 15. What two IQs seperate the middle 90 percent from the remainder of the distribution?
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Question 139725This question is from textbook Fundamentals of Algerbraic Modeling
: IQ scores have a normal distribution with a mean of 100 and a standard deviation of 15. What two IQs seperate the middle 90 percent from the remainder of the distribution?
part of my answer is: 90 - 100 / 15 = 0.66
and the second part is what i am having trouble with This question is from textbook Fundamentals of Algerbraic Modeling
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. What two IQs separate the middle 90 percent from the remainder of the distribution?
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Use your z-chart to find the z-value which has 5% of the population above it.
That would be 1.645
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Find th z-value which has 5% of the population below it.
That would be -1.645
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Find the x-values that correspond to these z-values:
z(x) = (x-u)/s
1.645 = (x-100)/15
x = 124.675
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-1.645 = (x-100)/15
x = 75.325
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Cheers,
Stan H.
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