Line graphs are composed of two axises, one vertical and one horizontal. When line graphs are used in algebra, the vertical axis is called the "y" axis and the horizontal axis is called the "x" axis. Almost any kind of data can be plotted on line graphs, but a common use of line graphs is to show a change over a period of time. With these graphs, the vertical axis is plotted with the amount of a variable and the horizontal axis represents time. Data is plotted according to coordinates established by the amount of the variable on the vertical axis and the time period on the horizontal axis. The coordinate points are then connected with a single line.
The primary objective of line graphs is to define raw data, making it easily understandable with a visual representation. By plotting data on a line graph, you assign it a vertical and horizontal value that corresponds to the raw data determining the graph. For instance, if tracking annual sales at a retail store, the data would be defined by the amount of sales in dollars and the months during which these sales took place.
The visual representation of data in line graphs allows users to easily interpret information over a given period of time. Once figures have been plotted on the graph and a line has connected all the points, users can visually analyze data that occurs over time without having to compare specific figures. For instance, monthly temperatures over the period of a year can be easily visualized by looking at the points on a line graph. The user can quickly ascertain the warmer and colder months based on viewing the graph, without having to compare specific temperatures. This also allows users to quickly and visually identify trends in data.
Line graphs show the rate of change to a specific data set over a period of time. For instance, line graphs are commonly used to check the changes in various weather patterns, including temperature, humidity and rainfall, over the course of a month or a year. Additionally, line graphs are often used to plot annual business profits and losses and to track spending throughout a year. Line graphs can also be used to track consumer spending and retail sales.