Two-way tables can be used to display information relating to several different options and categories.
The following table shows the number of right and left-handed children in a school year group of 70 children.
Boys | Girls | Total | |
---|---|---|---|
Right | 24 | 32 | 56 |
Left | 4 | 10 | 14 |
Total | 28 | 42 | 70 |
Notice how the totals add up in both directions.
There are 56 right-handed children.
There are 32 right-handed girls.
The probability that a child chosen at random is a right-handed girl is 32/70 = 16/35
Always remember to check that you have put the fraction into its simplest form.
Does that all make sense? Then, let's get started.