## 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?

1. amistre64

the bell curve is divided iinto whay ; 96% at the right ?

2. amistre64

i got an a intyping....honest lol

3. amistre64
4. amistre64

thats the reverse of what you wanted .... gotta learn to read :)

5. anonymous

lol so this wont help me ? thanks anyway:)

6. anonymous

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.