4. Page 4 of 14
:????????????????? ????? ?????? ???????
1.?????????? ??????? ????? ???????? ????????E1 ={11, 22, 33, 44, 55, 66}, P1 = 6/36
2.????????? ??????? ????? ???????? ????????11E2 ={46, 55, 64}, P2 = 3/36
3.???? ????? ????????? ??????? ?????? ???? ????????3E3 ={11}, P3 = 1/36
4.????? ????? ???????? ????????1???????? ???????? ????E4 ={11, 12, 13, 14, 15, 16}, P4 = 6/36
??????????? ??????? ????? ??????? ???? ????????? ????? ?????? ???? ???????
.?????????
6665646362616
5655545352515
4645444342414
3635343332313
2625242322212
1615141312111
654321-
:???????????? ????? ???????
???????? ????????? ????P (A B) = P (A) + P (B)
)??????? ?(???? ????????? ????? ??????? ?????? ????P (A B) = P (A) + P (B) - P (A B)
???? ?????? ???? ?????? ????? ????? ???????? ???????? ???? ???? ????? ?????? ??????? :??????4.
A = {1, 3, 5}, P (A) = 3/6
B = {5, 6}, P (B) = 2/6
AB = {5}, P (A B) = 1/6
P (A B) = 3/6 + 2/6 - 1/6 = 4/6
:??????
Male (M) Female
Smoking (S) 4 1 5
Not smoking 3 2 5
7 3 10
:?????? ????? ????? ???????? ???????? ????
P (M S) = P (M) + P (S) - P (M S) = 7/10 + 5/10 - 4/10 = 8/10
5. Page 5 of 14
( ???????? ??????????Conditional probability.)
( ??????? ????????? ??????? ??????? ??????? ??????? ???????? ???????? ????? ???????A)( ??????B.)(7)
( ??????? ????????A( ?????? )B)P (A / B) =
( ??????? ????????B( ?????? )A)P (B / A) =
= ????????? ??????????
???????? ?????????
???????? ???????
????????? ?????????:????????? ??????A, B????????? ???????.??????(8)
P (A / B) =
P (B / A) =
( :?????? ???? ????? ????A / B( = )B / A.?????? ?????? ???? ????? ????? ?)??
??????:????? ???????????? ???????)??????????? ????? ?????? ?(????????? ???? ???????? ??????:
1.?????????? ?????????(A)????????? ????4(B.)
P (A) = 6/36, P (B) = 3/36, P (A B) = 1/36
P (A or B) = P (A B) = P (A) + P (B) - P (A B) = 6/36 + 3/36 C 1/36 = 8/36
2.?????????? ?????????(A)??????????4(B.)
P (A) = 6/36, P (B) = 3/36, P (A B) = 8/36
P (A and B) = P (A B) = P (A) + P (B) - P (A B) = 6/36 + 3/36 - 8/36 = 1/36
3.?????????? ?????????(A)????????? ?????? ???? ??????4(B.)
P (A) = 6/36, P (B) = 3/36, P (A B) = 1/36
P (A/B) = = = 1/3
(7( ???????? )A and B???????? ????????? ???????? ???? )
(8???????? ??????? ?????? ?????? ???? ????? ???? ??????? ???? ???? ??????? ????? ?????? ???? ?????? ?????)????????? ?????? ??????? ????? ?????? ????? ??????? ????????? ?
6. Page 6 of 14
4.?????????4(B( ?????????? ????????? ?????? ?)A.)
P (B / A) = = = 1/6
5.?????????? ????????? ????
P (B / A) P (B) ? ????????? ????? ??????? ????? ?????????? ??????? ??????
( ???????????? ????? ???????Multiplication:)
?????????? ??????????????????? ????? ?????????
P (A B) = P (A) P (B)P (A B) = P (B) P (A / B)
P (A / B) = = P (A)P (A / B) =
:??????
?????????????
642??????
642??????
1284
:?????????
1.( ?????? ????????A( ?????? ?????? ????????? )B.)
P (A) = 4/12 = 1/3, P (B) = 6/12 = ? , P (A/ B) = 1/3 ? = 1/6 (9)
P (A / B) = P (A B) / P (B) = = 1/3 = P (A) ????????? ?????????
????? ??????? :?????)???????????? ?(???? ???? ?????? )???????? ?(????????? ???? ?????? ????????????????????? ?????? ????
??????????????? ???????? ???? ??????????? ?????????? ??????? ???? ???????? ???????????????? ???????? ?????????? ???????
(9= ???????? ???? )2/12