A, B: | |
(2.5) | |
n , :
P(A1+A2+A3+...+An)=P(A1)+P(A2)+P(A3)+...P(An )
(2.6)
. .
A | AB | B |
ABC | ||
AC | C | CB |
. 2.3
:
( + + ) = () + () + () - () - () - () + ().
1, 2, 3,..., n, , 1, :
P(A1) + P(A2) + P(A3) +... + P(An) = 1
(2.7) |
2.3 40000 , . 10000 , 8000 , 7000 , 6000 , 5000 , 4000 . , : 1. ? 2. ?
. :
û,
,
,
D ,
E ,
F .
,
, :
P(A) = 10000/40000 =0,25.
, :
P(B) = 8000/40000 = 0,20.
, :
P(C) = 7000/40000 = 0,175.
, :
P(D) = 6000/40000 = 0,15.
, :
P(E) = 5000/40000 = 0,125.
, :
P(F) = 4000/40000 = 0,10.
, B, C, D, E, F .
1., , , , , . , (2.5) : P( ) = P(A + B) = () + (B) = 0,25 + 0,175 = 0,425.
2. , , , , , , , . , (2.6) :
( ) = P(A + D + E + F) = P(B) + P(D) + P(E) + P(F) = 0,20 + 0,15 + 0,125 + 0,10 = 0,575.
|
|
. , (2. 3):
( ) = 1 - P( ) = 1 0,425 =
= 0,575.
: 1. P( ) = 0,425, 2. ( ) == 0,575.
2.4 52 . , , ?
. : - , - . () = 4/52; - () = 13/52; - P(AB) = 1/52.
.
... | ... | ... | ... | |||
. 2.4
- , .
, . 2.4 :
P(A + B) = P(A) + P(B) P (AB) = 4/52 + 13/52 - 1/52 = 16/52 = 0,3077
: , , 0,3077.
2.5. . ? ?
. .
. , .
- . N = 5, = 2, () = 2/5.
- . , N = 5, = 2 () = 2/5.
, , . .
, , , .
.
. , .
() = 2/5. , , . , ? N = 4, M = 1.
(/) () (). , (/)=1/4 , , . ()=4/52; (/)=4/16.
, , , ; , , , , , , , ..
|
|
, , . , , , .
:
P(AB) = P(A) × P(B), | |
P(A B) = P(A) × P(B) | (2.8) |