Scores on the Wechsler Adult Intelligence Scale, a standard IQ test, are approximately normal for the 20 to 34 age group with = 110 and a = 25. 1. What percent of this age group have an IQ less than 100? 2. What percent of this age group have an IQ between 90 and 115? 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%. 111