SOLUTION: Scores on a test are normally distributed with a mean of 63.2 and a standard deviation of 11.7. Find P81, which separates the bottom 81% from the top 19%.
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-> SOLUTION: Scores on a test are normally distributed with a mean of 63.2 and a standard deviation of 11.7. Find P81, which separates the bottom 81% from the top 19%.
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Question 1109908: Scores on a test are normally distributed with a mean of 63.2 and a standard deviation of 11.7. Find P81, which separates the bottom 81% from the top 19%. Answer by rothauserc(4718) (Show Source):
You can put this solution on YOUR website! to solve this problem using the normal distribution, the table of z-values is used
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a probability of 81 corresponds to a z-value of 0.87
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0.87 = (X - 63.2) / 11.7
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X - 63.2 = 0.87 * 11.7 = 10.179
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X = 63.2 + 10.179 = 73.379 approximately 73
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a score of 73 divides the bottom 81% from the top 19%
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