Suppose a new study has found a link between excessive smartphone use and poor mental health among teenagers. The study surveyed 500 high school students and found that those who spent more than 5 hours a day on their phones were more likely to report feelings of depression and anxiety. DOWNLOAD THE STUDY REPORT FROM THE JOURNAL OF ADOLESCENT HEALTH WEBSITE
Can we infer that "every teenager who uses a smartphone excessively will have poor mental health"? Yes, no, or maybe?