title: Randomization of a list
body: <p>I have a list of 20,000 students who are listed basis their academic standing in an excel sheet - undergraduate, graduate, PhD, part-time. I would like to get a random list of students. I can use the RAND function to create a list of random, however, there is a question of under and over representation. PhD students are the least in the list and undergraduates are the most, so there is a question of under and over-representation. How can I solve it?</p>