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

Question

Quizplus · Accepted Answer

The key feature that distinguishes a randomized experiment from an observational study is the random assignment of participants to different groups or treatments, which helps to eliminate selection bias and allows for causal inferences.

A Randomized Experiment Was Done by Randomly Assigning Each Participant