An Internet survey of 545 Hong Kong residents suggested that close daily monitoring of volatile financial affairs may not be good for your mental health (J. Social and Clinical Psychology 2002: 21: 116–128). Subjects who felt that their financial future was out of control had the poorest overall mental health, whereas those who felt in control of their financial future had the best mental health.
a. What is the population of interest for this survey?
b. Describe why this is an observational study.
c. Briefly discuss the potential problems with the sampling method used and how these problems could affect the survey results.