# Statistics and statistical graphs

### What graph goes with what type of variable

Data can be organised and displayed in tables, graphs, or by a set of numbers describing the distribution.

- The type of graph you use to display data depends on the type of data you are displaying.
- If you are displaying one categorical variable you should use a bar graph or a pie graph.
- Remember that pie graphs should only be used if all categories are present that is there is no category with zero responses.

- If you are displaying one quantitative variable you should use either a histogram or a stem and leaf plot.
- Remember stem and leaf plots are good for small quantities of data, while a histogram can be used with any size sample.

- If you have two quantitative variables you should use a scatter plot.
- If you have one quantitative variable and one categorical variable, you should draw a side by side box and whisker plot (boxplot).
- Remember any graph showing percentages, should always show the sample size.