I'm trying to solve this problem but I'm struggling to.
A university has 300 students enrolled. You sample 30 students and see that 20 are boys and 10 are girls. If the university had 150 male students and 150 females, what would be the probability of your observation? More generally, if there are N students enrolled in the university, B of which are boys and N − B girls, what is the probability that if you sample n (≤ N), then exactly b are boys and n − b are girls?
So from the sample we know that there are (approximating) 66% boys and 33% girls. But I don't know how to estimate the probability of this observation, what am I missing?