**Two-Way Tables** contain data which contain data held by both **row** and **column**.

Entries will belong to two different sets. For example, students in a class are asked how they arrive at school. The data is shown by method of transport, and by boy/girl:

Walk | Car | Bike | Bus | Train | TOTAL | |

Girls | 5 | 5 | 2 | 2 | 1 | 15 |

Boys | 4 | 2 | 3 | 5 | 2 | 16 |

TOTAL | 9 | 7 | 5 | 7 | 3 | 31 |

Each entry states membership of both sets: the number of *girls arriving by bus* is 2 out of the 31 students.

For the *class as a whole*, the most popular way to arrive is by walking (9 out of the total of 31).

But considering boys *only*, the most popular way to arrive is by bus (5 out of 16 boys). Make sure that you understand

Students in a class are surveyed for how they arrive at school. The two-way table, above, shows the results.

How many students arrived by bike?

All students are being considered.

A total of 5 students arrive by bike.

Answer: 5

Using the table, above, what, given a girl, is the least popular method of travelling to school?

Only girls are being considered.

Only 1 girl travels by train.

Answer: Train

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