Line Graph

Line graph also known as a line chart or line plot is a tool used for data visualization . It is a type of graph that represents the data in a pictorial form which makes the raw data more easily understandable. In a line graph data points are connected with a straight-line and data points are represented either with points or wedges. Some other examples of graphs are bar graphs, histograms, pie charts, line graphs, etc.

A line graph or line chart is a graphical representation of the data that displays the relationship between two or more variables concerning time. It is made by connecting data points with straight-line segments.

Parts of Line Graph

Parts of the line graph include the following:

• Title: It is nothing but the title of the graph drawn.
• Axes: The line graph contains two axes i.e. X-axis and Y-axis.
• Labels: The name given to the x-axis and y-axis.
• Line: It is the line segment that is used to connect two or more data points.
• Point: It is nothing but a point given at each segment.

Learn more about Point, Lines, and Plane.

How to Draw and Read a Line Graph?

Drawing a line Graph

To make a line graph we need to use the following steps:

1. Determine the variables: The first and foremost step is to identify the variables you want to plot on the X-axis and Y-axis.
2. Choose appropriate scales: Based on your data, determine the appropriate scale.
3. Plot the points: Plot the individual data points on the graph according to the given data.
4. Connect the points: After plotting the points, you have to connect those points with a line.
5. Label the axes: Add labels to the X-axis and Y-axis. You can also include the unit of measurement.
6. Add Title: After completing the graph you should provide a suitable title.

Reading a Line Graph

To read a line graph you need to follow the below given steps:

1. Understand the axes: First, you need to understand the X-axis and Y-axis of the graph.
2. Estimate the scale: Look at the values marked along each axis to determine the scale.
3. Estimate the values of data points: Look at the data points on the graph to estimate the values on the graph.
4. Analyze the pattern: Identify the pattern and analyze it.
5. Conclude: Based on the above step find conclusions.

Example: Draw a line graph for the given data

Answer:

The above diagram shows a line graph between No. of days and the number of absentees.

Types of Line Graph

Let us discuss the types of line graphs:

• Simple Line Graph
• Multiple Line Graph
• Compound Line Graph

Simple Line Graph

It is the most common type of line graph in which a single line represents the relationship between two variables over time. The above diagram is an example of a basic line graph.

Multiple Line Graph

It is the type of line graph in which we can represent two or more lines in a single graph and they can either belong to the same categories or different which makes it easy to make comparisons between them. Multiple line graphs also include a double line graph or we can say that a double line graph is also a multiple line graph.

An example of multiple graphs is shown below:

In the above graph sale of product A and B is shown in the same graph.

Compound Line Graph

It is a type of line graph in which multiple lines or data are combined into a single graph showing different categories or variables. The main aim of a compound line graph is to represent or display the relationship between different variables on a single graph.

A Compound Line graph example is shown below:

Advantages of Line Graph

Some of the advantages of using line graph are listed below:

• It helps to visualize the data.
• It provides a clear overview of the data.
• It becomes easy to make predictions using a line graph.
• It helps to compare the data more easily.

Note: Line graph is not suitable to show non linear relationship or complex data

Articles related to Line Graph:

• Statistics
• Bar Graphs
• Histograms
• Pie Chart

Solved Examples on Line Graph

Examples 1: Draw a line graph for the given data.

Solution:

Examples 2: Draw a line graph from the given data and answer the following questions.

(a) In the above graph find in which year the sale of product A is maximum.

(b)Find in which year the sale of product B is the minimum.

(c) Find in which year the sale of products A and B is the same.

Solution:

👁 Line Graph showing sale of Product A and B over the years

(a) In 2011, the sale of product A is maximum.

(b) In 2013, the sale of Product B is minimum.

(c) There is no year in which the sale of Product A and B is the same.

Examples 3: Draw a compound line graph for the given data.

Solution:

Examples 4: Draw a line graph for the given data

Solution:

Examples 5: Draw a line graph for the given data.

Solution: