Statistics and probabiltiy

8. (9 pts) A small sample of people is used to investigate the relation between age and stress. Each person ranked the stressfulness of their life on a scale from 1 to 10. X y x2 y xy age in years stress ranking 10 3 20 6 30 6 40 8 50 6 60 2 a. (4 pts) Find the regression equation - Bo + Bix. b. (3 pts) Find the correlation coefficient, r. What does the value of r tell you about the relation between stress and age? c. (2 pts) Interpret the slope of the regression line.7. (5 pts) Tramodol is a pain killer for moderate to moderately severe pain. When 6 subjects had repeated bone marrow biopsies, once with a placebo, and then with tramadol administered before the bone marrow biopsy, they evaluated their pain during the biopsy using the VAS scale (the lower the number, the less the perceived pain). The results are given in the table below: Subject Placebo Tramadol Difference (d) 22 13 36 27 aUAWNA 29 26 30 22 34 24 Is there sufficient evidence to conclude that the perceived pain is lower after Tramadol is taken? Use a = 0.01