Casio fx-9750G PLUS - Manual (Page 313)

285
u u u u u 2-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–12
+(n
2
–1)x
2 n–12
σ σ
df = n
1
+ n
2
– 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
o
1
: sample 1 mean
o
2
: sample 2 mean
x
1
σ
n -1
: sample 1 standard
deviation
x
2
σ
n -1
: sample 2 standard
deviation
n
1
: sample 1 size
n
2
: sample 2 size
x
p
σ
n -1
: pooled sample standard
deviation
df : degrees of freedom
o
1
: sample 1 mean
o
2
: sample 2 mean
x
1
σ
n -1
: sample 1 standard
deviation
x
2
σ
n -1
: sample 2 standard
deviation
n
1
: sample 1 size
n
2
: sample 2 size
df : degrees of freedom