HP 39g Master Manual page 152

Choose the test and the alternate hypothesis in the SYMB view of the
Inference aplet.
In this case we are working with a single
sample and we do not know the standard
deviation of the underlying population, so we
will use the Student-t test and the alternate
hypothesis that the mean of the real underlying population from which the
sample was drawn is not equal to that of the proposed underlying population.
Change now to the NUM SETUP view to enter
the required values. Rather than entering
them by hand, press the
have more than one copy of the Statistics aplet
(under other names) then you will be
presented with a list of aplets from which to choose.
Once you have chosen the aplet, you need to
nominate the column from which to import the
data. The default is column C1, which is what
we want in this case, but you can press the
key to select from a list of any other
columns which contain data. When you have
the correct column, press
Enter the population mean µ
that the test level is correct at 0.05 (5%).
If you now change to the NUM view you will see
the inferential data in numeric form. The test
Student-t value is given as 2.392 and the
probability of obtaining such a value as 0.0272.
The critical t values for this test level of 5% are
given as ± 2.093 and the critical boundaries for
the sample mean as 48.86 and 51.14.
The same information can be seen in a more
visual form if you change to the PLOT view.
The upper diagram shows the critical range for
the t values, while the lower horizontal line
shows the equivalent critical sample mean
range.
key. If you
.
= 50, and check
0
152
Sample t value is
outside rejection