Researchers conducted a study to determine whether magnets are effective in treating back pain. Pain was measured using the visual analog​ scale, and the results given below are among the results obtained in the study. Higher scores correspond to greater pain levels. Is this study an experiment or an observational​ study? Explain.
Reduction in Pain Level After Magnet​ Treatment: nequals=2020​, x overbarxequals=0.4930.493​, sequals=0.9590.959
Reduction in Pain Level After Sham​ Treatment: nequals=2020​, x overbarxequals=0.4420.442​, sequals=1.361.36