Observe the labels for the variables off to the right side. This is very informative and would have taken a long time to tally by hand, but there is much more we can learn about this issue when we look at proportions or percents. Let's click on another empty cell in the worksheet and select the Pivot Table option again from the Data menu. A dialogue like the one below will appear. Thus, the percents of Private and Public school graduates who are female are nearly the same.
Contingency tables describe the relationships between nominally measured variables.