HP 39g Graphing Calculator - Manual (Page 130)

Results The results are:
Result Description
Test T T-Test statistic.
Prob Probability associated with the
T-Test statistic.
Critical T Boundary value of T associated
with the a level that you supplied.
Critical
1
Boundary value of .v required by
the
0 . value that you supplied.
Two-Sample T-Test
Menu name T-Test: |al - ¡X2
The Two-sample T-Test is used when the population
standard deviation is not known. On the basis of statistics
from two samples, each sample from a different population,
this test measures the strength of the evidence for a selected
hypothesis against the null hypothesis. The null hypothesis is
that the two populations means are equal {H
q : pj = ^
2
)-
You select one of the following alternative hypotheses against
which to test the null hypothesis
<^2
>|i
2
//j ^ ^^2
9-14 Inference aplet