Question

An IQ test is known to have an approximate normal distribution with mean 100 and standard deviation 15. Using the Empirical Rule, about what percentage of test takers will have an IQ score between 85 and 115?

Answer 1

Answer: 68%

Explanation:

Empirical rule is basically using a bell curve along with mean and SD to find the center percentage. So take the mean right. 100 if you add 15 which is the SD you get 115 or 34.1% from 100 to 115. If you do the same thing but subtract this time 100-15=85 34.1% again from 85 to 100. So 85 to 115 is 34.1%+34.1%=68%