.
, . .
, . , , , . , , - . , , . , - .
() , , . , , , .
, () ( , ..). , , ( , ). , , .
,
- .
, , , .
() : . , , . , 1 : , , . : , , , , .
|
|
, , .
:
(, , , ..);
, (, , ).
I , .
, :
- ;
- , ;
- .
, :
___________
-- z / å X z
X = Ö ----------------
N (6.2.1)
z = -1 Þ ;
z = 0 Þ ;
z = 1 Þ ;
z = 2 Þ .
. .
, .
:
-- x1 + x2 + x3 + + xn å xi
X . = --------------------------------------- = ----------.
N n (6.2.2)
:
, . |
-- 4000 + 5000 + 6000 + 3000 + 5500 + 3500 27000
X . = ----------------------------------------------------- = --------- = 4500 .
6 6
() , .
-- x1* f1 + x2* f2 + x3 * f3 + + xn * fn å xi * fi
X . = ----------------------------------------------------- = ----------.
f1 + f2 + f3 + + fn å fi
(6.2.3)
:
, . xi | , . fi |
-- 1*3000+2*4000+3*5000+2*6000 38000
X ..= ------------------------------------------- = ---------- = 4750 .
1 + 2 + 3 + 2 8
() . . (, 养), , -- . .
|
|
:
, . xi | , xi | , . fi |
3000 | ||
3000 - 5000 | ||
5000 - 10000 | ||
10000 |
-- 1*2000+2*4000+2*7500+3*12500 62500
X .=--------------------------------------------- = ---------- = 7812,5 .
1 + 2 + 2 + 3 8
, , , . :
: , ;
: , ;
: , ;
: .
.
-- å xi * fi å Mi
X . = -------------- = ----------------.
xi * fi 1
å --------- å ---- * Mi (6.2.4)
xixi
:
, . xi | , . xi * fi |
-- 6000 + 8000 + 15000 + 18000 47000
X . = ------------------------------------------------- = ---------- = 4700 .
6000 8000 15000 18000 10
------ + ------ + ---------- + ---------
3000 4000 5000 6000
.
_____
-- n /
X . = Ö (. ). (6.2.5)
.
________________
/ __
-- / å (xi - x)2 * fi
X .= Ö ----------------------- (. ).
å fi
(6.2.6)
.
() (c , ..),
-- 1/2*x1 + x2 + x3 + + 1/2*xn
X . = -----------------------------------------------.
N 1 (6.2.7)
. ? . , :
-- å
R = --------------------------------------------------------------------------------.
å + å
, .
, . , . , , . , , , , .
:
1. .
2. , , . , : _
å xi * fi = x * å fi.
|
|
3. .
4. .