HotRod  -

If you want to describe relationships among categorical data, you can use a
Pivot Table to get summary counts for two characteristics that will help you
to visually decide whether a relationship exists. For a "test," a chi-square
test of independence might be appropriate.

If the data are numerical, then you could start with an XY (Scatter) chart
to visually describe the relationship between two characteristics, and you
could use the correlation coefficient (worksheet function CORREL) as a
summary measure. For a "test," the Regression tool provides an F-test for
overall fit and t-stats for individual coefficients.

-  Mike
http://www.mikemiddleton.com