Related Tutorial: Excel 2003 Line Graph Tutorial.
Line Graph Uses
Line graphs are often used to plot changes in data over time, such as monthly temperature changes or daily changes in stock market prices.
They can also be used to plot data recorded from scientific experiments, such as how a chemical reacts to changing temperature or atmospheric pressure.
Similar to most other graphs, line graphs have a vertical axis and a horizontal axis. If you are plotting changes in data over time, time is plotted along the horizontal or x-axis and your other data, such as rainfall amounts is plotted as individual points along the vertical or y-axis.
When the individual data points are connected by lines, they clearly show changes in your data - such as how a chemical changes with changing atmospheric pressure. You can use these changes to find trends in your dada and possibly to predict future results.
Following the steps in this tutorial walks you through creating and formatting the line graph seen in the image above.