Identifying individuals with a high risk of alzheimer’s disease

        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 (x) Cognitive Series (y)        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        Compute the   correlation to measure the degree of relationship between the two test   scores?   What   percentage of variance for the cognitive scores is predicted from the   7-Minute screen scores?