7-4-1

Graphing Single-Variable Statistical Data

7-4 Graphing Single-Variable Statistical Data

Single-variable data is data that consists of a single value. If you are trying to obtain the average height of the members of a single class, for example, the single variable would be height.

Single-variable statistics include distributions and sums. You can produce any of the graphs described below using single-variable data.

Before trying to draw any of the graphs described below, configure the graph setup using the procedures under “Configuring StatGraph Setups” on page 7-3-2.

Normal Probability Plot (NPPlot)

The normal probability plot plots data against a theoretical normal distribution using a scatter plot. If the scatter plot is close to a straight line, then the data is approximately normal. A departure from the straight line indicates a departure from normality.

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

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

•[Mark] specifies the shape of the plot mark.

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