A two-way frequency table sorts every sign-up card by two yes-or-no questions at once. A joint relative frequency is one cell over the grand total. A marginal relative frequency is a row or column total over the grand total. A conditional relative frequency is a cell over its own row or column total, the percent inside one group. Comparing the conditional percentages across rows shows whether the two questions are associated. The same table is a sample space: a card picked at random has probability cell over total, and conditional probability uses the group total.