There is a big exam tonight, and all of the 400 students are invited to attend the help session. From past experience, the instructor finds that 60% of the students are likely to attend the help session. She wants to reserve an appropriately sized room.
a. What is the expected value and variance for the number of students who will attend?
b. How many seats must be in the reserved room, so that the professor can be at least 90% sure that everyone who wants to attend will have a seat? (A computer is necessary to solve this problem numerically.)