# Obtaining Frequency Distributions - HP 49g+ User Manual

Graphing calculator.

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Coefficient of variation
The coefficient of variation of a sample combines the mean, a measure of
central tendency, with the standard deviation, a measure of spreading, and is
defined, as a percentage, by: V
Sample vs. population
The pre-programmed functions for single-variable statistics used above can be
applied to a finite population by selecting the
SINGLE-VARIABLE STATISTICS
of the variance and standard deviation which are calculated using n in the
denominator of the variance, rather than (n-1).
Example 3 -- If you were to repeat the exercise in Example 1 of this section,
using
rather than
Population
values for the mean, total, maximum, and minimum.
standard deviation, however, will be given by: Variance: 0.852, Std Dev:
0.923.

## Obtaining frequency distributions

The application
2. Frequencies..
frequency distributions for a set of data. Again, the data must be present in
the form of a column vector stored in variable ΣDAT. To get started, press
‚Ù˜ @@@OK@@@. The resulting input form contains the following fields:
:
the matrix containing the data of interest.
ΣDAT
the column of ΣDAT that is under scrutiny.
:
Col
:
the minimum class boundary (default = -6.5).
X-Min
:
the number of classes(default = 13).
Bin Count
:
the uniform width of each class (default = 1).
Bin Width
Definitions
To understand the meaning of these parameters we present the following
definitions: Given a set of n data values: {x
order, it is often required to group these data into a series of classes by
counting the frequency or number of values corresponding to each class.
(Note: the calculators refers to classes as bins).
= (s
/x)100.
x
x
Type: Population
screen. The main difference is in the values
as the
, you will get the same
Sample
Type
in the STAT menu can be used to obtain
, x
, ..., x
1
2
n
in the
The variance and
} listed in no particular
Page 18-5

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