Statistics problem

[adnanj]

Dear All

Please can any body help me to differentiate b/w independent and mutually exclusive events?

Regards

 

[PlanetMaster]

For starters, there is a link between mutually exclusive events- they can't both happen at once.
However, there is no link between independent events- they don't effect each other at all.
It might be easier to understand if you also consider non-mutually-exclusive events and dependent events.
If I draw one card from a deck, drawing an ace and drawing a king are mutually exclusive events- a single card cannot be both an ace and a king.
However, drawing an ace and drawing a spade are not mutually exclusive events- a single card can be both an ace and a spade.
If I draw one card, return that card to the deck, and then draw another card, the draws are independent of each other- the sample space is the same for both draws because I returned the first card to the deck.
If I draw one card, but do not return that card to the deck, and then draw another card, these events are dependent- the sample space is different since I didn't return the first card to the deck.
Say I drew an ace the first time.
Then there is one less card and one less ace in the deck, so the probabilities for the second draw have changed.
So mutually exclusive events are contrasted with non-mutually-exclusive events, asking whether one event excludes the other.
Independent events are contrasted with dependent events, asking whether one event effects the probability of the other.

 

[Saad Qadir]

Dude this wan an awesome explanation!
Thanks alot it even cleared many wrong concepts which i had=)

 

[adnanj]

thank u so much planet master..
it was the best explanation ever which i was unable to find even in any of the books...
can u also tell the equations of them..
like for mutually exclusive events, P(A)*P(B)=0

 

[PlanetMaster]

Sure!

For two independent events, A and B, the probability of both occurring together, P(A and B), is the product of the probability of each event.
P(A and B) = P(A) × P(B)

For two mutually exclusive events, A and B, the probability of either one occurring, P(A or B), is the sum of the probability of each event.
P(A or B) = P(A) + P(B)

 

[adnanj]

can anyone ans. these last questions ( i hope so)
2008 Q.7 (i) a ..... -10 would be on the left side of Y-axis or right side while drawing histogram?
Age of person.... discrete or continuous?
interquartile range.. advantage

 

[Saad Qadir]

Left side...
Discrete...
Advantage:It is a ueeful measure of spread od a distribution.Advantage is it is not affected by extreme values..

 

[adnanj]

if it would be on the left side, then the Y axis would come in between the histogram ????

confused !!!

 

[Saad Qadir]

dude it wont the value Is -10 <x>0 so O pe first rectangle is ova ...then make a new rectangle from 0 to 5..

 

[adnanj]

if age is discrete, then what about a person being 44 years and 5 months ????

 

[Saad Qadir]

Dude discrete means with in the given limits Now u can take dat as years and months...
So year Are whole Number..
And months are 12 so they are in the given limts

 

[Saad Qadir]

Dude it can be discrete as well as continiuos if teh question is given in integers lyk 2 yrs 3 yrs it is discret but if it is given 13 and a halff year and etc it si continious..depends upon the question