4.5.7 Mean Time to Failure Video
PROFESSOR: We're constantly asking how long we have to wait for things. And in the context of probability theory, it turns into the technical question called, the expected time to failure-- or the mean time to failure. Some examples might be that an insurance company wants to know, for a given policy holder, the expected time before that policy holder dies. A mechanical engineer wants to know the expected time before a button that's being pushed once per second is expected to fail. And I want to know when the part that my body shop has been waiting for is expected to come in. The mean time to failure problem, we can formalize in terms of flipping coins. So we're going to flip a coin until a head comes up. And we're going to think of a head as being a failure, and a tail as a success. So let's assume the probability of getting a head-- the probability of failure-- is p. Again, this is not a fair coin. It's a coin that may be biased in either directi...