1.6 Two-way tables
When data falls into more than one category or a learner is interested in investigating more than one variable, data cannot be organised easily in a frequency table.
Two-way tables are a way of sorting data so that the frequency of each category can be seen quickly and easily.
For example, a learner has asked 20 people about whether they like football and whether they like rugby. The results can be seen in the two-way table below.
From the table, it can be seen that there were 9 people who liked both rugby and football and 4 people who liked neither sport. It can also be seen that there were people who liked rugby but not football, and 5 people who liked football but not rugby.
Table 4 Do people who like football also like rugby?
| Like football | Do not like football | |
|---|---|---|
| Like rugby | 9 | 2 |
| Do not like rugby | 5 | 4 |
Activity 5 Interpreting a two-way table
Allow 5 minutes
Use the information presented in the two-way table below to answer the following questions.
- How many right-handed students are there in the class?
- How many students are there in the class in total?
Table 5 Do left-handed students like art?
| Left-handed | Right-handed | |
|---|---|---|
| Likes art | 2 | 12 |
| Do not like art | 1 | 10 |
Discussion
- There are 22 right-handed students in the class as this is the sum of the ‘right-handed’ column.
- There are 25 students in total. This is the sum of the ‘left-handed’ and ‘right-handed’ columns.
OpenLearn - Teaching mathematics
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