Which method of gathering data is described by the statement, “you do manipulate variables”? observed study experiment simulation indirect study consider the experiment:
a consumer advocacy group is curious about the effectiveness of pain medication in treating migraine headaches. they randomly give different doses of aspirin, tylenol, and ibuprofen to migraine sufferers. they then measure the results and compare.

what were the levels?

the migraine patients

the pain medication

the aspirin, tylenol, and ibuprofen

the dosages of the drugs

this is dosages of the drugs right?