Ten-year-old Andrea has an IQ of 130. This means that she
A) performed as well as or better than 98 percent of her same-age peers.
B) scored higher than 98 percent of all children.
C) scored three standard deviations above the mean.
D) performed as well as or better than 84 percent of her same-age peers.

Question

Quizplus · Accepted Answer

An IQ score of 130 places a person in the 98th percentile, meaning they performed as well as or better than 98 percent of their same-age peers. This percentile ranking is based on the normal distribution of IQ scores in the general population, where the mean is 100 and the standard deviation is 15. A score of 130 is two standard deviations above the mean, not three, making option C incorrect. Options B and D misrepresent the percentile ranking and the comparison group for IQ scores, respectively.

Ten-Year-Old Andrea Has an IQ of 130