answer a and b

4. The distribution of IQ scores of 12-year-olds is normal with a mean of 100 and a standard deviation of 16. The distribution of IQ scores for 20-year-olds is also unimodal and symmetric but with a mean of 120 and a standard deviation of 20. (a) Sketch the distribution of IQ score for 20-year-olds. Be sure to use the correct shape, center, and spread. [3 pts.] 40 60 80 100 120 140 160 180 200 0 20 IQ Scores (b) Jessica is a 12-year-old with an IQ of 132. Jessica's 20-year-old brother, Mark, has an IQ score of 144. Relative to their respective age groups, who had the higher IQ score? Show all your work clearly and justify your answer with a complete sentence. [4 pts.]