SOLUTION: Scores on the Stanford-Binet Intelligence scale have a mean of 100 and a standard deviation of 16, and are presumed to be normally distributed. A person who scores 68 on this sca

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Question 437211: Scores on the Stanford-Binet Intelligence scale have a mean of 100 and a standard deviation of 16, and are presumed to be normally distributed. A person who scores 68 on this scale has what percentile rank within the population? Show all work as to how this is obtained.
Answer by stanbon(75887) About Me  (Show Source):
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Scores on the Stanford-Binet Intelligence scale have a mean of 100 and a standard deviation of 16, and are presumed to be normally distributed. A person who scores 68 on this scale has what percentile rank within the population? Show all work as to how this is obtained.
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z(68) = (68-100)/16 = -2.5
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Find the p-value or left-tail of z= -2.5:
normalcdf(-100,-2.5) = 0.00621
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%ile score of raw score 68 is 0.621%ile
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Cheers,
Stan H.