Human intelligence is often measured with an Intelligence Quotient (IQ) test. IQ test scores are normally distributed with a mean of 100 and a standard deviation of 15. If one person were selected at random to take an IQ test, what is the probability that he or she would score between 90 and 110?

Step-by-step explanation:

Let X the random variable that represent the IQ scores, and for this case we know the distribution for X is given by:

Where and

We want to find this probability

And we can use the z score formula given by:

If we apply this formula to our probability we got this:

And we can find this probability with this difference:

And in order to find these probabilities we can use the normal standard table or excel and we got.  

answer: 42

use a calculator to find that 845/73 = 11.575

the whole part of the answer is 11. multiply this by 73 to get 11*73 = 803.

subtract that result from 845 to get 845 - 803 = 42