## mathmath333 one year ago How to read this symbol

1. mathmath333

How to read this symbol $$\Large P(E|F)$$

2. mathmath333

?

3. mathmath333

that is not fraction

4. welshfella

i think that's the Probability of F given that the event E has occurred. Conditional probability

5. anonymous

P of E such that F

6. mathmath333

this is related to this https://en.wikipedia.org/wiki/Conditional_probability

7. anonymous

|=such that

8. welshfella

- or have i got it the wrong way around??

9. mathmath333

i think u told the opposite

10. anonymous

yes

11. anonymous

it can be read as P of E such that of F

12. welshfella

yes probability of E given F

13. TuringTest

$P(A | B) = \text{Conditional probability of A given B}\\P(P\cap B)=\text{Probability of A and B (the intersection of A and B)}\\P(P\cup B)=\text{Probability of A or B (the union of A and B)}$

14. TuringTest

oops those P's should be A's lol

15. TuringTest

$P(A | B) = \text{Conditional probability of A given B}\\P(A\cap B)=\text{Probability of A and B (the intersection of A and B)}\\P(A\cup B)=\text{Probability of A or B (the union of A and B)}$

16. anonymous

lol

17. anonymous

nice work man! :)

18. ganeshie8

now that you know what $$P(A|B)$$ means, see if you can solve below problem |dw:1439733513721:dw|

19. ganeshie8

A person is picked from the village at random. Find the probability that the person is a man, given that the person is 70 years or older

20. mathmath333

i just started learning it . can't solve

21. ganeshie8

sure you can, you don't really need to know that formula you will discover that formula while solving the above problem

22. ganeshie8

you're given that the person is 70 or older, so "only look at that column" : |dw:1439734227337:dw|

23. ganeshie8

how many are 70 or older ? how many of them are men ?

24. mathmath333

5

25. mathmath333

70 old > 50 persons

26. ganeshie8

there are 25 people that are 70 or older right ?

27. mathmath333

yes 25