SOLUTION: IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. If a certain person has an IQ of 131, what percentage of the population has an IQ lower than h

Algebra ->  Probability-and-statistics -> SOLUTION: IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. If a certain person has an IQ of 131, what percentage of the population has an IQ lower than h      Log On


   

Question 464011: IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. If a certain person has an IQ of 131, what percentage of the population has an IQ lower than hers?
Found 2 solutions by stanbon, edjones:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. If a certain person has an IQ of 131, what percentage of the population has an IQ lower than hers?
--------------
z(131) = (131-100)/15 = 31/15 = 2.0667
------------------------------------------
P(x < 131) = P(z < 2.0667) = normaalcdf(-100,2.0667) = 98.06%
===================================
Cheers,
Stan H.
==========

Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
z=(131-100)/15=31/15=2.07
The area of the normal curve below 2.07 = 0.98 or 98% of the population has an IQ lower than hers.
.
Ed