Question

Two ad agencies want to understand issues that are important to students. Agency A will interview 50 students whose names are randomly chosen from school enrollment data. Agency B will interview 50 randomly selected people from those who respond to a social media posting. Which method will produce a fair sample of the student population and why?

Agency A, because students are convenient and easy to interview
Agency A, because names randomly selected from school data will be student names
Agency B, because people who respond to social media postings have strong opinions
Agency B,