This article describes how to go from a standard crosstab or grid table...
...to a table that displays an Average of all the columns per row:
Requirements
A table with rows and columns.
Method
1. Select your table.
2. Go to Data (or Appearance) > Rules in the object inspector.
3. To apply the rule, select the Plus (+) > Table Computations > Average of Each Row.
4. Select the Statistic to use (if different from the default).
5. Set the Position to place the new column on the left or right.
6. Press OK.
This rule adds an extra column to the right of the table which shows the Average of the statistics that are shown in the rows. Columns that are duplicates of other columns, for example, the NET column, are not included in the computation of the average. Note, this rule can only apply to a single statistic, and no significance tests are conducted on these averages.
Note, if you select Switch rows and columns on your table, the rule will no longer work due to the table dimensions changing. In this case, you will have to apply the Average of Each Column rule instead.