What is the range of IQ scores that fall in the middle of the distribution,encompassing 95 percent of all people?
A)100-125
B)90-120
C)80-140
D)70-130

Question

Quizplus · Accepted Answer

The middle of the distribution is typically considered to be the 50th percentile, which corresponds to an IQ score of 100. In order to encompass 95% of all people, we would need to look at the range that includes scores that fall between two standard deviations from the mean. In the case of IQ scores, the standard deviation is typically around 15 points. Two standard deviations above and below the mean would be 30 points, so the range for encompassing 95% of all people would be between 70 and 130. Therefore, the best choice is D.

What Is the Range of IQ Scores That Fall in the Middle