View Full Version : Mutually exclusive
patsygee1
Aug 16, 2009, 10:38 AM
The events X and Y are mutually exclusive. Suppose P(X) _ .05 and P(Y) _ .02. What is
the probability of either X or Y occurring? What is the probability that neither X nor Y will
happen?
s_cianci
Aug 16, 2009, 10:44 AM
If they're mutually exclusive, then that means they can't both happen ; if one happens, then the other doesn't and vice-versa. You have the individual probabilities for both X and Y. So it should now be easy to calculate the either/or probability. And once you have that answer, it's easy to determine the neither/nor probability as that's simply the complementary event to the either/or probability. I'm not going to give you the actual answers but if you want to attempt it I'll be happy to critique your work.
Unknown008
Aug 16, 2009, 10:45 AM
Mutually exclusive means that one cannot happen of the other happens. For example, if you toss a coin, you either have a head or a tail, not both.
1. The probability that either of the events occur = sum of probability.
2. The probability that neither events occur = Take the probability that either of the events occur from 1.
s_cianci
Aug 16, 2009, 10:51 AM
Mutually exclusive means that one cannot happen of the other happens. For example, if you toss a coin, you either have a head or a tail, not both.
1. The probability that either of the events occur = sum of probability.
2. The probability that neither events occur = Take the probability that either of the events occur from 1.Here you've been told how to do it, so go for it!
patsygee1
Aug 16, 2009, 10:55 AM
P(X or Y) = P(X) + P(Y)
P(X or Y) = .05 + .02 = .07 is the probability of x or y occurring
P(X or Y) = P(X) + P(Y) -1
P(X or Y) = .05 + .02 -1
P(X or Y) = -.93 probability neither x nor y will happen
Unknown008
Aug 16, 2009, 10:59 AM
The first one is correct.
However, the second one is not. You take 0.07 from 1, that is 1-0.07 and not the other way round. Probability is never negative. Probability ranges from 0 to 1 only.
s_cianci
Aug 16, 2009, 11:01 AM
The first one is correct.
However, the second one is not. You take 0.07 from 1, that is 1-0.07 and not the other way round. Probability is never negative. Probability ranges from 0 to 1 only.You got it!
patsygee1
Aug 16, 2009, 11:08 AM
Thanks for your help. Look forward to collaborating with you again
Unknown008
Aug 16, 2009, 11:11 AM
You're most welcomed! :)