HP 39gs Master Manual page 118

The effect of HRng
The effect of is rather different. It controls what range of data is
HRng
displayed on the graph, regardless of what axes are used. It is normally
set automatically to be the maximum and minimum values for the data.
For example histogram
were changed in
HRng
the left column representing the value of -2 as shown below.
The advantage of this is that it allows you to eliminate outliers from your
graph quite easily. However, eliminating them from your graph does
not eliminate them from inclusion in the calculation of the values that
appear in the page. To do that you would need to delete the
actual data itself.
Grouped data & HWidth
data
10 - 19
20 - 29
30 - 39
40 - 49
50 - 59
As with most calculators, the hp 39gs & hp 40gs provide only limited methods to deal with data of this form.
Summary statistics can be obtained by entering the mid-points of the intervals as the data values but these will
only be approximations, as nature of the data itself does not allow calculation of exact values.
The problem with using the mid points is that attempting a normal
will produce a series of isolated columns, each with width one unit. The
reason for this is that the calculator is assuming that there are 14 values
of exactly 15 (the mid-point) because it doesn't realize that the columns
extend the width of the interval 10 - 19.
However this can be fixed by using the
setting as outlined on the next
HWidth
page.
(shown right) has an
H1
to 0 to 7 then the graph will lose
PLOT SETUP
freq
14
26
37
23
17
of -2 to 7. If
HRng
One final note concerns grouped data. We saw earlier
how to deal with data displayed in a frequency table, but
did not deal with the case where the data was also
grouped into intervals or classes.
For example, suppose we want to analyze the set of
grouped data in the table on the left.
PLOT
118