Continuous data
Continuous data are data which can take any values. Examples include time, height and weight.
Because continuous data can take any value, there are an infinite number of possible outcomes. So continuous data must be grouped before they can be represented in a frequency table or statistical diagram.
Grouping continuous data
When choosing groups for the data, make sure that each piece of data can be placed in one (and only one) of the groups.
Investigation example
You are investigating the length of time each member of a class spends on the internet per week.
Look at the time groupings, usually referred to as the The range of values allowed within that band, when grouping data values.. Do you think they are correct?
These groups are incorrect, because the times of \({10}\) hours and \({20}\) hours can be entered into two different groups.
For example, the time \({10}\) hours can be entered into \(0 \leq time \leq 10\) (where time is less than or equal to \({10}\) hours), and also into \(10 \leq time \leq 20\) (where time is more than or equal to \({10}\) hours).
These groups are also incorrect, as the times \({0}\), \({10}\) hours and \({20}\) hours cannot be entered into any of the groups.
For example, the time \({10}\) hours cannot be entered either into \(0 \textless time \textless 10\) (where time is less than \({10}\) hours), or into \(10 \textless time \textless 20\) (where time is more than \({10}\) hours).
These groupings are correct. \({10}\) hours is included in the second group, but not the first, and \({20}\) hours is included in the third group, but not the second.