IQ scores form a normal distribution with µ = 100 and σ = 15.Individuals with IQs above 140 are classified in the genius category.What proportion of the population consists of geniuses?
A)0.9962
B)0.5038
C)0.4962
D)0.0038

Question

Quizplus · Accepted Answer

To find the proportion of the population that is classified as geniuses, we need to find the area under the normal distribution curve to the right of IQ = 140. We can use a standard normal distribution table or calculator to calculate the z-score:

z = (140 - 100) / 15 = 2.67

Using the standard normal distribution table, we find the proportion of the population with a z-score greater than 2.67 is 0.0038. Therefore, only choice D, 0.0038, is the correct answer.

IQ Scores Form a Normal Distribution with µ = 100