In each of the following scenarios, determine if the data are paired. a) Compare pre- 30-day exercise regimen and post- 30-day exercise regimen ratio of HDL/LDL for the same group of adults. b) Compare artery thicknesses at the beginning of a study and after 2 years of taking Vitamin E for the same group of patients. c) Assess the effectiveness of a diet regimen by comparing the before and after weights of subjects. d) A school board would like to determine whether there is a difference in average SAT scores for students at one high school versus another high school in the district. To check, they take a simple random sample of 100 students from each high school