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anonymous

  • 5 years ago

Some psychologists believe that a "genius" should be defined as anyone having an IQ over 140. If IQ scores are normally distributed with a mean of 100 and a standard deviation of 17, and if the population of the world is 6,575,000,000, how many geniuses are there in the world today?

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  1. amistre64
    • 5 years ago
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    the bell curve is divided iinto whay ; 96% at the right ?

  2. amistre64
    • 5 years ago
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    i got an a intyping....honest lol

  3. amistre64
    • 5 years ago
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    http://www.easycalculation.com/statistics/standard-deviation.php might be useful

  4. amistre64
    • 5 years ago
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    thats the reverse of what you wanted .... gotta learn to read :)

  5. anonymous
    • 5 years ago
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    lol so this wont help me ? thanks anyway:)

  6. anonymous
    • 5 years ago
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    We make the curve standard normal. \[(X-\mu)/(\sigma)\] (140-100)/17 that's a z score of 2.353. The probability of being that or higher can be looked up in a standard normal table. It is a probability of about .0094. Multiply this by the population of 6.575E9 to get the number of geniuses. I get 61,805,000 geniuses.

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