identify the type of study design described by each of the following statements: the association between average physical activity levels and coronary heart disease mortality was studied in illinois counties. a group of breast cancer cases were compared with a group of cancer-free women. all women were given a questionnaire about things like diet, healthcare access, and contraceptive use. a group of preschool-age children provided blood for measures of chemicals in their bodies. the children were followed for ten years' time, during which researchers annually collected data on cognition and behavior. researchers wanted to test a new pharmaceutical aimed at controlling blood sugar levels. participants were randomly assigned to a group that is given this newly developed medication, or to a group that received a different, older medication. both the investigator and the study participants were blinded as to which group each participant was in.