Which inductive generalization is stronger?

In a psychology class experiment to determine how many students suffer from test anxiety, student researchers visited three freshman-level courses and had students fill out survey questionnaires. Because 53% of respondents admitted to having test anxiety, it's safe to conclude that about half of all students on campus have test anxiety. In a psychology class experiment to determine how many students suffer from test anxiety, student researchers visited one freshman-level course, one sophomore-level course, and one senior course and had students fill out survey questionnaires. Because 53% of respondents admitted to having test anxiety, it's safe to conclude that about half of all students on campus have test anxiety.