IQ scores form a normal distribution with = 100 and = 15 . The proportion of the population classified as 'genius' is 0.0038 . What IQ score does a person need to be classified as 'genius'? about 140 127 at least 138 164.8 Question 15 (1 point) IQ scores form a normal distribution with = 100 and = 15 . Individuals with IQs between 90 and110 are classified as average. What proportion of the population is average? 0.7486 0.2486 0.5028 0.4972.