**Math 221 – Principles of Statistics**

Creating Histograms-With-Normal-Curves in SPSS

**
______________________________________________________________ **

** **

A histogram is a bar graph for __binned quantitative__ data, in
which the heights of the bars represent frequency or relative frequency, and
there are no gaps between the bars. Adding the appropriate Normal curve to the
histogram can help you
assess Normality.

To create a histogram-with-Normal-curve in SPSS:

1) Open a data file (in .sav or .por format) or type your
data in.

2) In either the Data Editor window or the Output Viewer
window, click on the “Graphs" menu and then on "Histogram..."

3) Select the variable of interest. Click on the
little arrow next to "Variable." This will move the variable into the
"Variable" box.

4) Click the check box next to "Display normal curve."

5) If you would like to add a title to your plot, click the
"Titles..." button. A new dialog box appears. Enter any titles or subtitles you
want to use, and click "Continue..."

6) Click "OK." The graph appears in the Output
Viewer. If you would like to change the label on the vertical axis, or change
the bin width or the anchor of the first bin, use the Chart Editor.

**NOTE: **The Normal curve that SPSS puts on the
histogram is the Normal curve with the same mean and standard deviation as the
data have. It turns out that __if__ the data are Normal, then the Normal
curve on the screen represents the particular Normal distribution the data come
from.

####
______________________________________________________________

** **

BYU-Idaho
mailto:brownd@byui.edu

232 Ricks Building 208-496-1839
voice

Rexburg, ID 83440 208-496-2005
fax

**Please
do not call me at home.**