⟩ Scenario A randomized experiment was done by randomly assigning each participant either to walk for half an hour three times a week or to sit quietly reading a book for half an hour three times a week. At the end of a year, the change in Participants blood pressure over the year was measured, and the change was compared for the two groups.?
This is a randomized experiment rather than an observational study because:
► a) Blood pressure was measured at the beginning and end of the study.
► b) The two groups were compared at the end of the study.
► c) The participants were randomly assigned to either walk or read, rather than choosing Their own activity
► d) A random sample of participants was used.
Answer - c
