Texas Instruments TI-82 STATS User Manual

Tables and Reference Information A–53
826DEC~1.DOC TI-83 international English Bob Fedorisko Revised: 10/26/05 2:20 PM Printed: 10/27/05 3:09
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
xx
S
=
−
12
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
nn
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
nSxnSx
df
p
=
−+−() ()
11
2
22
2
11
S
nn
Sx
p
=+
11
12
df n n=+−
12
2
and Sxp is the pooled variance.
2.SampTTest

Texas Instruments TI-82 STATS Specifications

General

Type	Graphing Calculator
Display	LCD
Resolution	96 x 64 pixels
Characters	16 x 8
Processor	Zilog Z80
Programming	TI-BASIC
Memory	28 KB RAM
Power	4 AAA batteries
Connectivity	Link port