Evidence for an Alternative Therapy? Use the following information for Exercises 67–69. A company called QT, Inc. sells “ionized bracelets,” called Q-Ray Bracelets, that it claims help to ease pain by balancing the body's flow of “electromagnetic energy.” QT, Inc. claims that Q-Ray Bracelets can ease pain caused by cancer, restore wellbeing, and provide many other health benefits. The Mayo Clinic decided to conduct a statistical study to determine whether the extravagant claims for Q-Ray Bracelets were justified.10 In the study, 305 subjects wore the Q-Ray “ionized” bracelet and 305 wore a placebo bracelet (identical to the ionized bracelet except for the ionization) for four weeks, at the end of which certain measures of pain were evaluated and compared between the treatments. The subjects, upon entry to the study, were randomly assigned to receive either the ionized bracelet or the placebo bracelet.

Question 1.165

69. Does this statistical study represent an experimental study or an observational study? Write a sentence explaining why.

1.3.69

This study is an experimental study because the subjects were randomly assigned to either a treatment or a control.