**Start revising A-level & GCSE with 7 million other students**

# Graphs and Charts 1

## You are here

***Please note: you may not see animations, interactions or images that are potentially on this page because you have not allowed Flash to run on S-cool. To do this, click here.***

## Graphs and Charts 1

These are sometimes called **bar charts.**

These are a good way of looking at the spread of data and are very easy to draw.

Remember to number your axes evenly just as you would with a normal algebraic graph. Here's an example:

**The marks obtained by 30 pupils in a maths test are as follows:**

**First tally them:**

**Now draw your frequency diagram:**

**With grouped data, the bottom axis should be numbered continuously as on a normal graph with the bars covering the group they represent!**

**Line Graphs** are only used for discrete data and are simply a line (instead of a bar) for each data value showing total frequency.

Again, these are done in the same way as Frequency Diagrams but you do not draw the bars.

Instead you put a little cross where the middle of the bar would have been then join all the crosses together. **Here's what a Frequency Polygon would look like for the example used in Frequency Diagrams above:**