U=(X-A)/C,
A=25,C=0.5
U=(23.5-25)/0.5=-3
u
|
f
|
fU
|
(U-Ū)
|
(U-Ū)2
|
f(U-Ū)2
|
-3
|
1
|
-3
|
-3.444444
|
11.86417
|
11.86417
|
-2
|
6
|
-12
|
-2.444444
|
5.97528
|
35.85168
|
-1
|
23
|
-23
|
-1.444444
|
2.08641
|
47.98743
|
0
|
48
|
0
|
-0.444444
|
0.19753
|
9.48144
|
1
|
39
|
39
|
0.55556
|
0.30864
|
12.03696
|
2
|
20
|
40
|
1.55556
|
2.41976
|
48.3952
|
3
|
5
|
15
|
2.55556
|
6.53088
|
32.6544
|
4
|
2
|
8
|
3.55556
|
12.642
|
25.284
|
|
Σf=144
|
ΣfU=64
|
|
|
Σf(U-Ū)²=223.5558
|
Ū=(ΣfU)/Σf=(64/144)=0.44444
σU=(Σf(U-Ū)/n)1/2 = (223.5558/144)1/2
σU = 1.24598
σX=CσU =(0.5)(1.24598)=0.62299