Alex, Ben, and Cam all rate their happiness on an interval scale running from 0-10. Alex's happiness is 5. Ben's is 7.5. Cam's is a perfect 10. Which of the following statements is NOT true?
1) Alex's happiness is 5.
2) Ben's happiness is 7.5.
3) Cam's happiness is a perfect 10.
4) All of the above statements are true.