, , . |
.???.... |
, . |
, . |
( ).. (D), (σ). .. ( , ) |
. ???
腅.???
= Σ Xi * Pi, M =-∞ ∫+∞ X*f(x)dx, f(x)..
f(x) , f(x)dx dx x = xo.
f(x)dx - , .
腅..
D = Σ (Xi X)2 * Pi, .
D =-∞ ∫+∞(X X)2*f(x)dx .
.
σ = √ D ???
?
.
.
1 ................... ............................ 2 ................... ............................ 3 ................... ............................ |
, , : = 0,95 +/-2σ = ,
( - 2σ < x < + 2σ) = 0,95
. +/- +/- . 0,68 0,9973.
, =??? +/??? /.
.....................................
......................................................................
..................................
|
|
(X) - ,
(Sx) (σ).
Sx2.
(X) (Sx)