Can choosing the right music make wine taste better? This question was investigated by a researcher at a university in Edinburgh (www.decanter.com/news). Each of 250 volunteers was assigned at random to one of five rooms where they were asked to taste and rate a glass of wine. In one of the rooms, no music was playing and a different style of music was playing in each of the other four rooms. The researchers concluded that cabernet sauvignon is perceived as being richer and more robust when bold music is played than when no music is heard.

a. Is the study described an observational study or an experiment?

b. Can a case be made for the researcher’s conclusion that the music played was the cause for the higher rating? Explain.