Texas Instruments Voyage 200 Guide Book

TI-89 / TI-92 Plus / Voyage™ 200 PLT Statistics with List Editor App ˆ Tests Menu 163
2-SampFTest
Description
2 ˆ (
Tests) Æ 9:2.SampFTest for the TI-89
ˆ (Tests) Æ 9:2.SampFTest for the TI-92 Plus / Voyage™ 200 PLT
2.SampFTest (two-sample Û-test) computes an Û-test to compare two normal population
standard deviations (s
1
and s
2
). The population means and standard deviations are all
unknown.
2.SampFTest, which uses the ratio of sample variances Sx1
2
/Sx2
2
, tests the null
hypothesis H
0
: s
1
=s
2
against one of the alternatives below.
¦ H
a
: s
1
ƒs
2
¦ H
a
: s
1
<s
2
¦ H
a
: s
1
>s
2
Data Inputs
List 1, List 2 Lists containing the data used in the calculations.
Freq 1, Freq 2 Frequency values for the data in List 1 and List 2. The default is 1. All
elements must be integers | 0. Each element in the frequency
(Freq) list
is the frequency of occurrence for each corresponding data point in the
input list specified in the
List field.
Alternate Hyp
(
s
1
π
ππ
πs
2
, s
1
<
<<
<s
2
, s
1
>
>>
>s
2
)
Three alternate hypotheses against which the null hypothesis (H
0
: s
1
=s
2
)
may be tested.
Results
(Calculate or Draw)
Calculate: Display numerical and symbolic test results in a dialog box.
Draw: Draw a graph of the test results.
Stats Inputs
Sx1, Sx2 Known standard deviations for data sequences in List 1 and List 2.
n1, n2 Size of the samples.
Alternate Hyp
(
s
1
π
ππ
πs
2
, s
1
<
<<
<s
2
, s
1
>
>>
>s
2
)
Three alternate hypotheses against which the null hypothesis (H
0
: s
1
=s
2
)
may be tested.
Results
(Calculate or Draw)
Calculate: Display numerical and symbolic test results in a dialog box.
Draw: Draw a graph of the test results.
Data and Stats Outputs
Outputs Stored to Description
F f Calculated Û statistic for the data sequence.
P Value pval Least probability at which the null hypothesis can be rejected.
Num df numdf numerator degrees of freedom = n1-1.
Den df dendf denominator degrees of freedom = n2-1.
Sx1, Sx2 sx1, sx2 Sample standard deviations of the data sequences in List 1 and List 2.
x1, x2 x1_bar
x2_bar
Sample means of the data sequences in List 1 and List 2.
n1, n2 n1, n2 Size of the samples.

Texas Instruments Voyage 200 Specifications

General

Type	Scientific
Form factor	Pocket
Product color	Blue
Display resolution	128 x 240 pixels