1. Compute the correlation for the following data. Then, add another point (12, 8) and calculate the new correlation. Explain how the two correlations differ. 2. Below are three scores for each of nine subjects. Compute the correlation between A and B, A and C, and B and C. Add 5 to each score in distribution A and then multiply by 2. Recalculate the correlation between A and B. How has the correlation between A and B changed? 3. Correlation studies are often used to help determine whether certain characteristics are controlled more by genetic influences or by environmental influences. These studies often examine adopted children and compare their behavior with the behaviors of their birth parents and their adoptive parents. One study examined how much time individuals spend watching TV (Plomin, Corley, Defries, & Fulker, 1990). The following data are similar to results obtained in the study. Amount of Time Spent Watching TV Adopted Children Birth Parents Adoptive Parents 2 0 1 3 3 4 6 4 2 1 1 0 3 1 0 0 2 3 5 3 2 2 1 3 5 3 3 a. Compute the correlation between the children and their birth parents. b. Compute the correlation between the children and their adoptive parents. c. Based on the two correlations, does TV watching appear to be inherited from the birth parents or is it learned from the adoptive parents? 4. Identifying individuals with a high risk of Alzheimer's disease usually involves a long series of cognitive tests. However, researchers have developed a 7 Minute Screen which is a quick and easy way to accomplish the same goal. The question is whether the 7 Minute Screen is as effective as the complete series of tests. To address this question Ijuin et al. administered both tests to a group of patients and compared the results. The following data represent similar results to those obtained in the study. Patient 7-Minute Screen Cognitive Series A 3 11 B 8 19 C 10 22 D 8 20 E 4 14 F 7 13 G 4 9 H 5 20 I 14 25 a. Compute the correlation to measure the degree of relationship between the two test scores? b. What percentage of variance for the cognitive scores is predicted from the 7Minute screen scores