You plan to sample from the 15,000 students enrolled at your university to compare the proportions of medical students and law students who believe that social media has a positive impact on their lives.
(a) Suppose that you use random numbers to select students but you stop selecting law students as soon as you have 30, and you stop selecting biology students as soon as you have 30. Is the resulting sample a simple random sample? Why or why not?
(b) What type of sample is the sample in (a)? What is the advantage of using this type of sampling compared to other sampling methods?