Contingency Tables

A useful method for classifying data from a count is through contingency tables.

With contingency tables, probabilities can be determined by knowing other data from the table.


A car dealership is giving away a trip to Rome to one of their 120 best customers. In this group, 65 are women, 80 are married and 45 married women.

1What is the probability that the trip will be awarded to a bachelor?

2If the winner is married, what is the probability that it is a woman?

Contingency Table

Contingency Table

Contingency Table Operations

Contingency Table Solution