<p>If there is a class ith 320 seats and only 310 are taken, then why is there a waitlist of 40 people???????????</p>
<p>It could be for a number of reasons. For example, wait-listing is often times determined by the availability of labs/discussion sections. For example, if 50 people want to get into a section that only holds 20, then 30 people will be placed on the waitlist, not only for that section, but for the lecture itself, regardless of how many actual seats the lecture itself holds. {As a corollary, you should understand that what often times prevents people from taking a particular class is not the availability of seats within the lecture itself, but the availability of seats in the particular labs/sections that you are able to attend. It doesn't matter if the lecture itself has available seats if your course schedule prevents you from getting into the lab/section that you need.}</p>
<p>Other possibilities include the class holding some seats in reserve for those with priority - i.e. people who are declared majors, upper-division people, grad students, etc. Hence, some classes will hold some seats open only for those people. If those seats remain unfilled, then they will be opened to the general student body.</p>
<p>what class is this anyway?</p>
<p>Stats 21 right?</p>