Classify a statistical study as either an observational or a designed experiment. Statistical Study In a clinical trial, 780 subparticipants suffering from high blood pressure were randomly assigned to one of three groups. Over a one-month period, the first group received the experimental drug, the second group received a placebo, and the third group received no treatment. The diastolic blood pressure of each participant was measured at the beginning and at the end of the period and the change in blood pressure was recorded. The average change in blood pressure was calculated foreach of the three groups and the three averages were compared. A political pollster reports that his candidate has a 10% lead in the polls with 10%undecided