Casio CFX-9970G User Manual page 304

18 - 6
Tests
u u u u u 2-Sample t Test
2-Sample
sample standard deviations for two populations are unknown to test the hypoth-
esis that the two samples were taken from the same population. The 2-Sample
Test is applied to standard normal distribution.
This formula is applicable when the sample is not pooled, and the denominator is
different when the sample is pooled.
Degrees of freedom
effect.
The following applies when pooling is in effect.
The following applies when pooling is not in effect.
Perform the following key operation from the statistical data list.
t
Test uses the sample means, variance, and sample sizes when the
o – o
1 2
t =
x x
% %
2 2
1 n –1 2 n –1
+
n n
1 2
df
and
df n n
= + – 2
1 2
(n –1)x
%
1 1
x =
%
p n–1
n
1
1
df =
2 2
C (1–C )
+
–1 –1
n n
1 2
x
%
2
1 n–1
n
1
C =
x x
% %
2 2
1 n–1 2 n–1
+
n n
1 2
3(TEST)
t
2( )
2(2-S)
o
: sample 1 mean
1
o
: sample 2 mean
2
x
: sample 1 standard deviation
%
n
1 -1
x
: sample 2 standard deviation
%
n
2 -1
n
: sample 1 size
1
n
: sample 2 size
2
x
differs according to whether or not pooling is in
%
p n
-1
+(n –1)x
%
2 2
n–1 2 2 n–1
+ n – 2
2
t
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