mutually exclusive

[defeated_soldier]

what does mutually exclusive means in probability ?

when we call two events are mutually exclusive ?

suppose, the CASE-1,

person A is playing a die. he got '2' when he rolled die

person B is playing ANOTHER die. he got '3' when he rolled die.

are these two events are mutually exclusive ?






NOW suppose, the CASE-2,

person A is playing a die. he got '4' when he rolled die.

person B is playing SAME die. he got '5' when he rolled die.

are these two events are mutually exclusive ?


Please explain.....its very complicated concept.

thank you

 

[royhaas]

Mutually exclusive simply means that two events cannot occur at the same time.

 

[defeated_soldier]

Mutually exclusive simply means that two events cannot occur at the same time.

Yes....i know this definition. but i can not co-relate with this in the real problem.

for example :

does CASE-1 is mutually exclusive ?

I think NO....because person A may get '2' and also person B can get '2'. so, both of them get '2' at the same time(they are having different dices) ......so this is not mutually exclusive.


does CASE-2 is mutually exclusive ?
I think NO....because person A may get '3' and also person B can get '3' though they roll in turns. so, both of them get '3' but they wont be at the same time(because they are rolling in turns)......so this is not mutually exclusive.


Is my explanation correct ?

If my explanation is correct then tell me when this mutual exclusion occurs!!

does they event have to occur really at the same time ?
does the evets have to be having different value at the same time to become mutual exclusion ?


see, i am heavily confused now. the keywords....."same time", "same value" is making trouble.

can anybody explain in a simpler way with some examples ?

Thank you

 

[defeated_soldier]

Mutually exclusive simply means that two events cannot occur at the same time.

if i expand this comment.

do you want to mean the two events which gives the same output ?(for example...2 dices are producing 2 at the same time ).....do you mean like this ?


OR


any two evetns (may be one die is produicing 2 and other is producing 3) does not occur at the same time ?


please explain.

thank you

 

[royhaas]

If two events cannot happen at the same time, they are mutually exclusive. Two events, period. For example: if A is the event that a student has a C average in statistics, and B is the event that a student is failing statistics, then A and B are mutually exclusive.

 

[defeated_soldier]

If two events cannot happen at the same time, they are mutually exclusive. Two events, period. For example: if A is the event that a student has a C average in statistics, and B is the event that a student is failing statistics, then A and B are mutually exclusive.

the example you have shown is called "independency"......does mutual exclusion and independency are same ?

 

[royhaas]

The example is one of mutual exclusion, since you cannot have a C average in statistics and be failing statistics at the same time. You should read your textbook more. Mutually exclusive means the intersection of the two events is the null set. Independence means you can multiply the marginal probabilities to get the probability of joint occurrence.