SOLUTION: Suppose that IQ scores in one region are normally distributed with a standard deviation of 14. Suppose also that exactly 60% of the individuals from this region have IQ scores of g

Question 1159337: Suppose that IQ scores in one region are normally distributed with a standard deviation of 14. Suppose also that exactly 60% of the individuals from this region have IQ scores of greater than 100(and that 40% do not).
What is the mean IQ score for this region? Carry your intermediate computations to at least four decimal places. Round your answer to at least one decimal place.
Answer by Boreal(15235) (Show Source): You can put this solution on YOUR website!
z=(x-mean)/sd
60th percentile is a z-score of 0.2533
therefore, 0.2533=(100-mean)/14
so 3.5469=100-mean, multiplying through by 14
the mean = 100-3.5469=96.45 or 96.5 is the mean
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