formal Scores on the Wechsler Adult Intelligence Scale a standard IQ test are approximately normal for the 20 to 34 age group with p 110 and o 25 1 What percent of this age group have an IQ less than 100 normal caf 999 100 110 115 344578234 46 1 normalcaf 999 4 0 1 2 What percent of this age group have an IQ between 90 and115 HGMAI 3 Find the 80th percentile of the IQ scores distribution of 20 to 34 year olds 4 Find the IQ score which separates the lowest 25 of all IQ scores for this age group from the highest 75 160 10 20 30 40 50 60 70