There are many summary measures available for scale variables, including:

- Measures of central tendency. The most common measures of central tendency are the mean (arithmetic average) and median (value above and below which half the cases fall).
- Measures of dispersion. Statistics that measure the amount of variation or spread in the data include the standard deviation, minimum, and maximum.

Open the Frequencies dialog box again.

Click Reset to clear any previous settings.

Select Household income in thousands (income) and move it into the Variable(s) list.

Click Statistics.

Click Mean, Median, Std. Deviation, Minimum, and Maximum.

Click Continue.

Deselect (uncheck) Display frequency tables in the main dialog box. (Frequency tables are usually not particularly useful for scale variables since there may be almost as many distinct values as there are cases in the data file.)

Click OK to run the procedure.

The Frequencies Statistics table is displayed in the Viewer window.

In this example, there is a large difference between the mean and the median, with the mean being over 25,000 greater than the median. This indicates that the values are not normally distributed. We can visually check the distribution with a histogram.