Use the following scenarios for questions 1 through 3:

Researchers want to determine if there is a relationship between whether or not a woman smoked during pregnancy and the birth weight of her baby.

A. Researchers examined records for the past five years at a large hospital.

B. A large high school wants to know the proportion of students who currently use illegal drugs. Uniformed police officers asked a random sample of200students about their drug use.

C. A company develops a new dog food. The company wants to know if dogs would prefer its new food over the competition's dog food. One hundred dogs, who were food deprived overnight, were given equal amounts of the two dog foods: the new food versus the competitor's food. The proportion of dogs preferring the new food versus the competitor's was recorded.

1 - Which scenario above describes an experiment? Explain why.

2 - Which scenario describes a survey? Will the results of the survey be accurate? Why or Why not?

3 - The remaining scenario is an observational study. Is it possible to perform an experiment to determine if a relationship exists? Why or why not?