Assume that adults have IQ scores that are normally distributed with a mean of 105 and a standard deviation 20. Find P4 which is the IQ score separating the bottom 4% from the top 96%.

The IQ score that separates the bottom 4% from the top96% is P4=____(round to the nearest hundredth as needed)

Question

Assume that adults have IQ scores that are normally distributed with a mean of 105 and a standard deviation 20. Find P4 which is the IQ score separating the bottom 4% from the top 96%.

The IQ score that separates the bottom 4% from the top96% is P4=____(round to the nearest hundredth as needed)

anonymous · Answer

Ok so what you are looking for is the IQ at which 4% of all the total probabilities are covered. If you would look at the area, it would seem somehow like this
|dw:1398423079157:dw|

anonymous · Answer

On my calculator, I have a function for this, called inverseNorm, I am not sure about you

anonymous · Answer

And entering invNorm(0.04,105,20) where parameters stand for (area,mean,standard deviation) I get an answer of 69.9863 round it up to the amount you need.

However make sure you can calculate something like this yourself, with the device you are using...