SOLUTION: I am stuck :( The distribution of scores on a standardized aptitude test is approximately normal with a mean of 480 and a standard deviation of 100. What is the minimum score n

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Question 578182: I am stuck :(
The distribution of scores on a standardized aptitude test is approximately normal with a mean of 480 and a standard deviation of 100. What is the minimum score needed to be in the top 15% on this test? Carry your intermediate computations to at least four decimal places, and round your answer to the nearest integer

Answer by ad_alta(240) About Me  (Show Source):
You can put this solution on YOUR website!
We just need the number of standard deviations that exclude 85% of the area. Using a z-score table, we get z=1.04 (about). Thus, (x-480)/100=1.04 and x=584 is the minimum score.