Postby Technomancer » Mon Apr 11, 2005 10:20 am
Well, you shouldn't leave things to the last minute- give yourself time to study. A full lesson on basic probability and statistics usually takes up the first chapter or two in most textbooks (which I will not duplicate). Peruse those first, and then come back with more specific questions about what you have trouble with. Any introductory book on probability and random processes would do, but Papoulis' or Garcia's books are probably the easiest to find. Stark and Woods' book though is unquestionably the best, although you may have trouble finding it.
For your particular example, the solution is simple. If you assume there is no replacement, then the total probability is simply the product of the proabilities of drawing a red card for each independant trial.
That is:
(9/11)*(8/10)*(7/9)*(6/8)*(5/7)
Each time you draw red card, the total number of red cards is reduced as is the total number of cards. If drawing with replacement is assumed then obviously the solution is trivial.
So what should you know?
1)The axioms of probability (and their set theoretic def'ns)
2)Joint/conditional probabilities and independence
3)Baye's theorem
4)Combinatorics.
All of these subjects are well covered in any elementary text book on probability and statistics, so a trip to your library is in order.
The scientific method," Thomas Henry Huxley once wrote, "is nothing but the normal working of the human mind." That is to say, when the mind is working; that is to say further, when it is engaged in corrrecting its mistakes. Taking this point of view, we may conclude that science is not physics, biology, or chemistry—is not even a "subject"—but a moral imperative drawn from a larger narrative whose purpose is to give perspective, balance, and humility to learning.
Neil Postman
(The End of Education)
Anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that my ignorance is just as good as your knowledge
Isaac Aasimov