2. In a study of stability of IQ scores, a large group of individuals is tested one at age 18 and again at age 35. The following results are obtained.

Age 18: average score = 100, SD = 15

Age 35: average score = 100, SD = 15, r = 0.80

a) Estimate the average score at age 35 for all the individuals who scored 115 at age 18.

b) Predict the score at age 35 for an individual who score 115 at age 18.