A researcher conducts comprehensive interviews with 80 students at your school to determine the financial status of students in general at your school. In this example, what is the population?

I don't understand what they are asking. How do I find the population when (I think) there is information missing?

I think the question has to do with understanding what the term "population" means in statistical analysis. The population is simply the number of individuals involved in the study. Does this help?