In the course of a conversation, you observe that three of your friends like horror movies. Horror movies happen to be your favorite type of movie as well. You also know that all of these friends were born in the same week that you were, even in the same year.
An astrology-loving friend hypothesizes that people born in that week like horror movies more than other genres of movies. You decide to use the scientific method to test this hypothesis.
What should you do next?