___% of the population scores between 85 and 115 on IQ tests.
A) 50
B) 68
C) 95
D) 99

Question

Quizplus · Accepted Answer

According to the normal distribution, within one standard deviation of the mean (which includes scores between 85 and 115), approximately 68% of the population falls. Therefore, choice B, 68, is the correct answer. Choice A (50) is incorrect because that would be the percentage of the population that falls within one half of a standard deviation of the mean. Choice C (95) would be the percentage of the population that falls within two standard deviations of the mean. Choice D (99) would be the percentage of the population that falls within three standard deviations of the mean.

___% of the Population Scores Between 85 and 115 on IQ