A frequency table helps us to organise and order data. We often use tally marks to help us construct frequency tables.
A teacher conducted a survey of shoe sizes of an S1 class. The results are shown below:
|Shoe sizes of S1 class|
These results are quite difficult to read. Organising the data in a frequency table helps show at a glance how many of each size there were.
Here is the data for the ages of customers in the Bitesize coffee shop.
|Ages of customers in 1 hour period|
We could show this data in a table with one number in each row, but it would have a lot of rows!
We can group the ages together so that we have fewer categories.
This is the same set of data put into groups:
When choosing intervals for the data sets try not to make the intervals too big or too small.
You could use the above intervals to draw a frequency chart:
Here is the data for the length of time (to the nearest minute) people took to fill in an application form.
|Length of time (minutes)|
Make a frequency table of this data.
(The answer below starts with 11-15, 16-20, etc. The interval choice is sometimes up to you)