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.
i | 1 | 2 | 3 | 4 | 5 |
fi |
i () (i = ),
fi () (i = ).
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:
1, 2, ,n, :
n , .. n = 2+1, = +1;
n , .. n = 2 =(++1)/2, . . .
2. :
3-5 | |
5-7 | |
7-9 | |
9-11 | |
:
1. .
2. .
3. .
4. .
, , , , , . .
% . ( ) | % . ( ) | i | fi | i × fi | i - `x | (i - `x)2 | (i - `x)2 × fi |
-3,18 | 10,11 | 151,68 | |||||
-1,18 | 1,39 | 33,41 | |||||
0,82 | 0,67 | 32,27 | |||||
2,82 | 7,95 | 103,38 | |||||
S | 320,76 |
=(15×4+24×6+48×8+13×10)/
(15+24+48+13)=718/100=7,18%
D = s2=((4-7,18)2×15+(6-7,18)2×24+(8-7,18)2×48+(10-7,18)2×13)/(15+24+48+13)=320,76/100=3,21
s - , 1,79%.
:
V=(s/`)×100%=(1,79/7,18) ×100%=25%
7% 9%, , .
. 100 7,18%; - 1,79%, -25%. , .
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15-20 | 12+N |
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