Suppose you were to read the following news story: "Researchers compared a new drug to a placebo for treating high blood pressure, and it seemed to work. But the researchers were concerned because they found that significantly more people got headaches when taking the new drug than when taking the placebo. Headaches were the only problem out of the 20 possible side effects the researchers tested."
a. Do you think the research used an observational study or a randomized experiment? Explain.
b. Do you think the researchers are justified in thinking the new drug would cause more headaches in the population than the placebo would? Explain.