Question

IQ scores in Fishtopia are normally distributed with a mean of 85 and a standard deviation of 20. Find the approximate number of people in the country (assuming a total population of 31,700) with an IQ higher than 123. (Round your answer to the nearest person.) For full credit, you must calculate the z-score for the given data point. Then you can determine the appropriate probability using either your calculator or the table, but clearly state which method you are using and how you used it (ie. if using your calculator, write down what function you used). Then provide your final answer with appropriate units.

Answer 1

population of country = N = 31700

The following information has been provided:

We need to compute The corresponding z-value needed to be computed is:

Therefore, we get that

Number of people above the IQ 123 = N*.0287

Number of people above the IQ 123 = 31700*0.0287

Number of people above the IQ 123 = 909.79

Number of people above the IQ 123 = 910 people