Remember that the last column and the last row in a two-way frequency table show the total number of respondents that fall into a particular category.
See solution.
Practice makes perfect
Let's start by recalling that we use two-way frequency tables to display and interpret relationships between paired categorical data. Remember that in categorical data, each piece of data falls into one of the categories. Let's consider an example.
Movies or Video Games?
Grade
Movies
Video Games
Total
Middle School
36
53
89
High School
76
35
111
Total
112
88
200
Each cell of a two-way frequency table tells us about the frequency of one combination of categories. This means that a two-way frequency table shows all of the possible combinations of categories together with their frequency.
We can see that the last row and column show the total number of respondents that fall into a particular category. In other words, the final row contains the sums of each column, and the final column consists of the sums of each row. Additionally, the cell in the last column and the last row shows the total number of respondents.
Movies or Video Games?
Grade
Movies
Video Games
Total
Middle School
36
53
89= 36+ 53
High School
76
35
111= 76+ 35
Total
112= 36+ 76
88= 53+ 35
200
Therefore, the structure of a two-way frequency table allows us to write an equation for each row and each column. In other words we are able to complete the table using the column and row totals.
