Tables and Reference Information A-53
8399APXA.DOC TI-83 international English Bob Fedorisko Revised: 02/19/01 1:25 PM Printed: 02/19/01 1:40 PM
Page 53 of 58
The following is the definition for the
2
.
SampTTest
. The
two-sample
t
statistic with degrees of freedom
df
is:
t
x
x
S
=
−
1
2
where the computation of
S
and
df
are dependent on
whether the variances are pooled. If the variances are not
pooled:
S
Sx
n
Sx
n
=
+
1
2
1
2
2
2
df
Sx
n
Sx
n
n
Sx
n
n
Sx
n
=
+
−
+
−
1
2
1
2
2
2
2
1
1
2
1
2
2
2
2
2
2
1
1
1
1
otherwise:
Sx
n
Sx
n
Sx
df
p
=
−
+
−
(
)
(
)
1
1
2
2
2
2
1
1
S
n
n
Sx
p
=
+
1
1
1
2
df
n
n
=
+
−
1
2
2
and
Sxp
is the pooled variance.
2-SampTTest
