Casio fx-9750G PLUS - Page 313

285
uu
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u2-Sample t Test
2-Sample t Test compares the population means when the population standard
deviations are unknown. The 2-Sample t Test is applied to t-distribution.
The following applies when pooling is in effect.
t =
o
1
– o
2
n
1
1
+
n
2
1
x
p n–1
2
σ
x
p n–1
= σ
n
1
+ n
2
– 2
(n
1
–1)x
1 n–1
2
+(n
2
–1)x
2 n–1
2
σ
σ
df = n1 + n2 – 2
The following applies when pooling is not in effect.
t =
o
1
– o
2
x
1 n–1
2
σ
n
1
+
x
2 n–1
2
σ
n
2
df =
1
C
2
n
1
–1
+
(1–C )
2
n
2
–1
C =
x
1 n–1
2
σ
n
1
+
x
2 n–1
2
σ
n
2
x
1 n–1
2
σ
n
1
Perform the following key operations from the statistical data list.
3(TEST)
2(t)
2(2-S)
Tests 18 - 6
o1 : sample 1 mean
o2 : sample 2 mean
x1 σ n-1 : sample 1 standard
deviation
x2 σ n-1 : sample 2 standard
deviation
n1 : sample 1 size
n2 : sample 2 size
xp σ n-1 : pooled sample standard
deviation
df : degrees of freedom
o1 : sample 1 mean
o2 : sample 2 mean
x1 σ n-1 : sample 1 standard
deviation
x2 σ n-1 : sample 2 standard
deviation
n1 : sample 1 size
n2 : sample 2 size
df : degrees of freedom