In statistics, the value assigned to the variable is an observation or characteristic that differs from one individual to the next. There may be more than one variable in a statistical study. Consider this statistical study: Suppose a doctor has developed a new medicine to treat migraine headaches. To test the effectiveness of the drug, the doctor gathers volunteers who experience migraines and gives a dose that varies from one volunteer to the next. During the study, when volunteers experience a migraine, they take their prescribed dose of medicine and report whether the pain level is reduced. What are the variables in this study? Choose one answer. Pain level and migraine headache Dosage level and migraine headache Dosage level and pain level

In this study, the variables include the dosage level and pain level. The dosage level is the amount of the medicine given to each volunteer, which differs from one individual to another. Pain level refers to the intensity of the migraine that each volunteer experiences and reports after taking the medicine. Both of these aspects are crucial for analyzing the effectiveness of the new treatment. When evaluating the effectiveness of a medical treatment like in this study, the interplay between dosage and pain level is vital. Researchers must be cautious of the placebo effect—where volunteers may report improved pain simply due to their expectations. Additionally, varying individual responses to medication underscore the importance of clinical trials in capturing a comprehensive view of a drug's efficacy across a diverse population.