STA215H5 Lecture 15: Sample spaces, events, probability, rules of probability
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Ra(cid:374)do(cid:373) (cid:373)ea(cid:374)s that (cid:449)e do(cid:374)"t k(cid:374)o(cid:449) (cid:449)hat the out(cid:272)o(cid:373)e is: coi(cid:374): do(cid:374)"t k(cid:374)o(cid:449) if it is goi(cid:374)g to la(cid:374)d o(cid:374) heads/tails. It does(cid:374)"t (cid:373)ea(cid:374) that all the out(cid:272)o(cid:373)es a(cid:396)e e(cid:395)uall(cid:455) likel(cid:455: heights of people are not equally likely. Trial: every time you do something that gives you a random output: repeated many times. Law of large numbers can be used to determine where probabilities come from. Heads will come up 50% of the time if many trials are done. Lln only applies in long term: thousands. When talking about the averages, there are not a lot of trials. The outcome of my trial is not going to affect someone else"s trials because our trials are independent. Copying off of tests would be dependent because the trials are affected. If 2 events are mutually exclusive, they cant happen at the same time. Independent and mutually exclusive are both disconnected but they are different form each other.
