# Mean stand dev mean stand dev conclusions 68 of iq

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conclude from the Empirical rule?mean – stand. dev. = 100-15 = 85mean + stand. dev. = 100 + 15 = 115Conclusions: 68% of IQ scores in (85,115)95% of the IQ scores are in (70,130),
Interpretation of the standard distribution:Chebyshev’s Theorem and Empirical rule - ExampleSuppose IQ scores have a mean of 100 and a standard deviation of 15. Whatcan we conclude from the Chebyshev’s theorem?(mean) – 2·(stand. dev.) = 100-2×15 = 70(mean) + 2·(stand. dev.) = 100 + 2×15 = 130(mean) – 3·(stand. dev.) = 100-3×15 = 55(mean) + 3·(stand. dev.) = 100 + 3×15 = 145Conclusion: 75% of IQ scores are in the interval (70,130), and 89% of IQscores are in the interval (55,145)If it is given that IQ scores are approximately bell-shaped, what do weconclude from the Empirical rule?mean – stand. dev. = 100-15 = 85mean + stand. dev. = 100 + 15 = 115Conclusions: 68% of IQ scores in (85,115)95% of the IQ scores are in (70,130), and 99.7% of IQ scores are in theinterval (55,145)
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