13.1. , .
13.2. (, ), , , , .. = P{ X = }, =1.
, . .
. , . (, ) , , .
13.3.
1 | 2 | 3 | 4 | |
0,1 | 0,3 | 0,2 | 0,4 |
13.4. , (n, p) k {1,2,, n } (=)= .
:
0 | 1 | k | n | |||
= =1.
13.5. , ( >0), k {0,1,2,} (= k)= .
0 | 1 | k | |||
, = = =1.
, , p (0< p <1), . .
13.6. , p (0< p <1), k N (=k)= , . :
1 | 2 | 3 | n | |||
= = =1.
13.7. 2 . .
P2(0)= = ; P2(1)= = =0,5; P2(2)= = .
0 | 1 | 2 | |
:
.
13.8. . 0,6. 3- .
p =0,6, q =0,4, k =3, ()= =0,42*0,6=0,096.
14
|
|
, , . (), . . : , .
14.1. . =()= .
, = .
, = ,
, .
14.2. , .
14.3. ,
3 | 5 | 2 | |
0,1 | 0,6 | 0,3 |
=3*0,1+5*0,6+2*0,3=3,9.
14.4. , p.
A . =1 (A ) p =0 , ..
1 | 0 | |
p | q |
= 1∙ p +0∙ q = p.
.., .
14.5. : =.
C | |
1 |
=*1=.
14.6. , , .
14.7. :
( )=∙ .
( )= = = ∙().
14.8. , ,, , , i =1,2,, n
{ , ,, }= { } { } { } (1)
= , i =1,2,, n, (1)
{ < , < ,, < }= { < }{ < } { < }, :
(, ,, ) = () ()... () (2)
, ,, , .
14.9. 2- :
()= ∙ .
14.10. 2- :
(+)= + .
14.11. 14.9 14.10 .
|
|
14.12. , 2- .
, , , . :
1 | 2 | 3 | 4 | 5 | 6 | |
= = (1+2+3+4+5+6)= = . (+)=2* =7.
14.13. n : = np.
n . i - , i =1,2,, n. = + ++ . = . 14.4 M Xi = p, i =1,2,, n, = = np.
14.14. D X =M(X -M X)2.
14.15. = .
14.16. . . :
D X = M(X - M X)2 = M(X 2 - 2 X ∙ M X + (M X)2) = M(X 2) - 2M(X ∙ M X) + M(M X)2= =M(X 2)-M X ∙ M X + (M X)2 = M(X 2) - (M X)2.
D X = M(X 2) - (M X)2.
14.17. ,
X | 2 | 3 | 5 |
P | 0,1 | 0,6 | 0,3 |
M X =2*0,1+3*0,6+5*0,3=3,5; M(X 2)= 4*0,1+9*0,6+25*0,3=13,3;
D X =13.3-(3,5)2=1,05.
14.18. 0:
DC=0
DC = M(- M)2= M(- )2=0.
14.19. ,
D( X) =C2 D X.
D(C)=(- CM X)2=((X- M X)2) = C2 M(X - M X)2 = C2D X.
14.20. 2-
D(+ Y)=D +D Y.
D(X + )=((X + Y)2) (M(X + Y))2= M(X2 + 2 XY + Y2) - (M X + M Y)2= =M(X)2+2 Y +M(Y 2)-(M(X)2+2 Y +M(Y)2)= M(X 2)-(M X)2+M(Y 2)- (M Y)2= = D X +D Y.
14.21. .
14.22. n , p , .
D X = npq.
X n , = , A i - , , .
D X = ,
1 | 0 | |
p | q |
, = p M = p, D =M()-( )2= p - p 2 = p (1- p)= pq. D X = = npq.
14.23. 10 , 0,6. - .
n =10, p =0,6, q =0,4, D X = npq =10*0,6*0,4=2,4.
14.24. k :
=M().
=M(), =M(). D X = - .
14.25. k (X -M X)k.
=[(X -M X)k].
, = [ X -M X ]= M X - M X =0, = [(X -M X)2]= D X. = - .
:
= -3 +2 ,
= -4 +6 -3 .