Line Graph, Bar Graph & Pie Graph

A line graph is a unique graph which is commonly used in statistics. It represents the change in a quantity with respect to another quantity. For example, the price of different flavours of chocolates varies, which we can represent with the help of this graph. This variation is usually plotted in a two-dimensional XY plane. If the relation including any two measures can be expressed utilizing a straight line in a graph, then such graphs are called linear graphs. It is also called a linear graph.

It signifies a straight line on the graph. It is an algebraic equation consisting of a constant or a product of constant and a single variable. The equation of the linear graph is given by, y = mx + c, where m is the slope of the equation and c is its Y-intercept. In the equation y = mx + c, if we put each value of x, it provides the value of y and we get an ordered pair (x, y) of numerals.

Line Graph Definition

A line graph is a graph that utilizes points and lines to represent change over time. It is a chart that shows a line joining several points or a line that shows the relation between the points. The graph represents quantitative data between two changing variables with a line or curve that joins a series of successive data points. Linear graphs compare these two variables in a vertical axis and a horizontal axis.

Different Parts of Line Graph

Title: The title explains what graph is to be plotted.

Scale: The scale is the numbers that explain the units utilized on the linear graph.

Labels: Both the side and the bottom of the linear graph have a label that indicates what kind of data is represented in the graph. X-axis describes the data points on the line and the y-axis shows the numeric value for each point on the line.

Bars: They measure the data number.

Data values: they are the actual numbers for each data point.

How to Make a Line Graph?

If we have created data tables, then we draw linear graphs using the data tables. These graphs are plotted as a series of points, which are later joined with straight lines to provide a simple way to review data collected over time. It offers an excellent visual format of the outcome data collected over time.

To plot a linear graph follow the below steps.

  1. Use the data from the data-table to choose a suitable scale.
  2. Draw and label the scale on the vertical (y-axis) and horizontal (x-axis) axes.
  3. List each item and place the points on the graph.
  4. Join the points with line segments.

Line Graph Example

Question: Sketch the solution on number line |x + 2| ≤ 5.


Given, inequality |x + 2| ≤ 5

Step 1: Change the inequality into a compound inequality

– 5 ≤ x + 2 ≤ 5

Step 2: Subtract 2 from all three sides to get

– 5 – 2 ≤ x + 2 – 2 ≤ 5 – 2

= – 7 ≤ x ≤ 3

Step 3: Place this value on a number line