2.2 Summary Statistics for Two Categorical Variables

Calculate summary statistics from two-way tables.

• A joint relative frequency in a two-way table is a cell frequency divided by the total for the entire table.
• A marginal relative frequency in a two-way table is a row total divided by the total for the entire table or a column total divided by the total for the entire table.
• A conditional relative frequency is a relative frequency computed by restricting to a particular level, or category of interest. A conditional relative frequency can be a cell frequency in a row divided by the total for that row or it can be a cell frequency in a column divided by the total for that column.

Compare summary statistics for two categorical variables.

• Summary statistics for two categorical variables can be used to compare distributions for evidence of association between the two variables.

Justify a claim using summary statistics for two categorical variables.

• Summary statistics for two categorical variables may reveal information that can be used to justify claims about the variables in context.