18
u
u
u
u
u
2-Sample
t
Test
2-Sample
t
Test
compares the population means when standard deviations are unknown.
The
2-Sample
t
Test
is applied to t-distribution.
t
=
o
1
–
o
2
x
1
n
–
1
2
"
n
1
+
x
2
n
–
1
2
"
n
2
o
1
: mean of sample 1
o
2
: mean of sample 2
x
1
"
n
-1
: standard deviation of sample 1
x
2
"
n
-1
: standard deviation of sample 2
n
1
: size of sample 1
n
2
: size of sample 2
This formula is applicable when the sample is not pooled, and the denominator is different
when the sample is pooled.
Degrees of freedom
df
and
x
p
"
n
-1
differs according to whether or not pooling is in effect.
The following applies when pooling is in effect.
df
=
n
1
+
n
2
–
2
x
p n
–
1
=
"
n
1
+
n
2
–
2
(
n
1
–
1)
x
1
n
–
1
2
+(
n
2
–
1)
x
2
n
–
1
2
"
"
The following applies when pooling is not in effect.
df
=
1
C
2
n
1
–
1
+
(1
–
C
)
2
n
2
–
1
C
=
x
1
n
–
1
2
"
n
1
+
x
2
n
–
1
2
"
n
2
x
1
n
–
1
2
"
n
1
Perform the following key operation from the statistical data list.
3
(TEST)
c
(T)
c
(2-Smpl)
Содержание STAT 2
Страница 30: ...30 u u u u uInput Example u u u u uResults...
Страница 56: ...56 Calculation Result Output Example p F distribution probability...
Страница 64: ...Examples...
