(X) = np D (X) = npq. :
- ;
- .
:
:
- ;
- .
p q, pq £ 0,25.
1. , , 10 3. , 25 .
. X , .
:
10 15
x
0 = 10 25
, , , ( (16)):
, s = 3, D (X) = s 2 = 9. :
, : p (X £ 25) ³ 0,8256.
: p (X £ 25) ³ 0,8256.
2. : nu = nx; nv = ny; nuv = nxy. nuv ¹ 0 0 ui × vj.
U / V | 3 | 2 | 1 | nu | |||
2 | 6 | ||||||
1 | |||||||
1 | |||||||
nv | n =50 |
3. :
, ,
4. :
, , :
; r .
3. Y X :
|
|
- r = 0, X Y ( );
- 0 < | r | £ 0,6, X Y ;
- 0,6 < | r | £ 0,8, X Y ;
- 0,8 < | r | < 1, X Y ;
- , X Y .
. Y X . X Y
X / Y | nx | ||||||
1,5 | |||||||
2,5 | |||||||
3,5 | |||||||
ny | n =50 |
Y X, X Y.
.
1. X, Y , : , h 1 = 0,5; h 2 = 20, nxy = 10 x * = 2,5; y * = 80.
0,06. , 500.
. X .
:
x
0 a= 300 500 5000
a = np D (X) = npq, . , a = 5000×0,06 = 300; D (X) = 5000×0,06×0,94 = 282.
:
, : p (X > 500) £ 0,3611.
: p (X > 500) £ 0,3611.
3. , , 10 4 . , 5 15 .
. , .
:
5 5
x
0 5 a =10 15
, s = 4, , , D (X) = s 2 = 16; , ( (18)):
: p (| X 10| £ 5) ³ 0,36.
72 .
. X .
:
|
|
36 36
x
0 a= 36 72 1200
a = np D (X) = npq, . , a = 1200×0,03 = 36, D (X) = 1200×0,03×0,97 = 34,92.
, , = 36, , :
p (X > 72) = 1 p (X £ 72) = 1 p (| X 36| £ 36) £ 1 =
= 34,92/ 36 2 = 0,0269.
: p (X > 72) £ 0,0269.