7-4-2

Graphing Single-Variable Statistical Data

Histogram Bar Graph (Histogram)

A histogram shows the frequency (frequency distribution) of each data class as a rectangular bar. Classes are on the horizontal axis, while frequency is on the vertical axis.

kGraph Parameter Settings (page 7-3-3, 7-3-4)

•[XList] specifies the list that contains the data to be graphed.

•[Freq] specifies the frequency of the data.

Tap [OK].

e

A dialog box like the one shown above appears before the graph is drawn. You can use this dialog box to change the start value (HStart) and step value (HStep) of the histogram, if you want.

Med-Box Plot (MedBox)

This type of graph is often called a “Box and Whisker” graph. It lets you see how a large number of data items are grouped within specific ranges.

minX Q1 Med Q3 maxX

Label

Meaning

Description

minX

minimum

The data’s smallest value

Q1

First Quartile

The median between minX and Med.

 

 

The median of all the data values. If you have 13 values, for

Med

Median

example, this is the value at position seven (six values left

 

 

and right).

 

 

 

Q3

Third Quartile

The median between maxX and Med.

maxX

maximum

The data’s largest value

• The lines from minX to Q1, and from Q3 to maxX are called “whiskers”.

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