25.
.
: D (X) = M (X - M (X)) 2. :
D (X) = M (X 2) - (M (X)) 2.
.
1. : D (C) = 0.
2. , : D (CX) = C^2*D (X).
3. :
D (X+Y+Z) = D (X)+D (Y)+D (Z).
4. - : D (C+X) = D (X).
s 2 , .
5. D(X-Y)=D(X)+D(Y)
26.
,
M=n*p, D=n*p*q ( : = npq)
( 0 < p < 1, q = 1 p; m = 0, 1, 2,..., n.
27.
, .
M=D=a ( : = a)
()
28.
, .
( 0 < p < 1, q = 1 p; m = 0, 1, 2,....)
29
, .
()
30.
(1). ( ), (2).
(1) , - , x
( - , , I .)
(2)
= (<). F(x)=P(X<x)
F-
F(x) - .
F(x) - , .
.
F(x) , .. x2>x1 F(x2)>=F(x1)
F(x)=0; F()=0
F(x)=1; F()=1
, . 1. F(x)
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32.