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u u u u u 2-Sample t Test
t
2-Sample
Test compares the population means when the population standard deviations
are unknown. The 2-Sample
The following applies when pooling is in effect.
o
– o
t
1
=
σ
x
2
p
n–1
(n
σ
x
=
p
n–1
df
n
n
=
+
– 2
1
2
The following applies when pooling is not in effect.
o
– o
1
t =
σ
x
2
1 n–1
+
n
1
df =
2
C
+
n
–1
1
x
1
C =
σ
x
2
1 n–1
n
1
Perform the following key operations from the statistical data list.
3(TEST)
c(T)
c(2-Smpl)
1-2-13
Tests (TEST)
t
Test is applied to
2
1 +
1
n
n
1
2
σ
–1)x
+(n
–1)x
2
1
1
n–1
2
n
+ n
– 2
1
2
2
σ
x
2
2 n–1
n
2
1
2
(1–C )
n
–1
2
σ
2
n–1
n
1
σ
x
2
2 n–1
+
n
2
20011101
20010101
t
-distribution.
o
: mean of sample 1
1
o
: mean of sample 2
2
σ
x
: standard deviation of
1
n
-1
sample 1
σ
x
: standard deviation of
2
n
-1
σ
2
sample 2
2
n–1
n
: size of sample 1
1
n
: size of sample 2
2
σ
x
: pooled sample standard
p
n
-1
deviation
df
: degrees of freedom
o
: mean of sample 1
1
o
: mean of sample 2
2
σ
x
: standard deviation of
n
1
-1
sample 1
σ
x
: standard deviation of
n
2
-1
sample 2
n
: size of sample 1
1
n
: size of sample 2
2
df
: degrees of freedom
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