4.In a study of the stability of IQ scores, a large group is tested once at age 18 and then again at age 35, and the following results are obtained:

age 18: average score?100, SD?15

age 35: average score?100, SD?15,r?0.8.

(a) (3 pts) Estimate the average IQ score at age 35 for all the individuals who scored 120 at age 18. Explain/show your work.

(b) (2 pts) What do you predict the IQ score at age 35 would be for an individual who scored 120 at age 18?Include a margin of error. Show your work.

(c) (3 pts) What is the approximate percentage of the individuals who scored 120 at age 18 that scored 120or aboveat age 35? What assumptions are you making about the IQ data in making your calculations?

4. In a study of the stability of IQ scores a large group is tested once at age 18 and then again at age 35, and the following results are obtained: age 18: average score a 100, SD z 15 age 35: average score 2 100, SD % 15, 'r z 0.8. (a) (3 pts) Estimate the average IQ score at age 35 for all the individuals who scored 120 at age 18. Explain/show your work. (b) (2 pts) What do you predict the IQ score at age 35 would be for an individual who scored 120 at age 18? Include a margin of error. Show your work. (c) (3 pts) What is the approximate percentage of the individuals who scored 120 at age 18 that scored 120 or above at age 35? What assumptions are you making about the IQ data in making your calculations