1. SUMMARISING NUMERICAL DATA
12 Further mathematics
SUMMARISING NUMERICAL DATA

2. Dot points and stem plots
Even when we have constructed a frequency table, or a histogram to display a set of
numerical data, we are still left with a large amount of information to digest. The way we
overcome this problem is to summarise the information and describe the essential features of the distribution with just a few numbers.
We call these numbers summary statistics.
The two most commonly used types of summary statistics may be classified as:
1 measures of centre (at which point is the distribution centred?)
2 measures of spread (how are the scores in the distribution spread out?).

3. Dot points and stem plots

4. Dot points and stem plots

5. Dot points and stem plots

6. Dot points and stem plots

7. WORK TO BE COMPLETED
Exercise 2A Questions 2,4,5