Bar Graph - Data Collection Method

The collection, presentation, analysis, organization and interpretation of observations or data is known as statistics. The statistical data can be represented by various methods such as tables, bar graph, pie charts, histograms, frequency polygons etc.

In the upcoming discussion, the collection of data through a bar graph is discussed.

Bar graph

The pictorial representation of data (generally grouped), in the form of vertical or horizontal rectangular bars, where the length of bars are proportional to the measure of data, are known as bar graphs (also known as bar charts). The bars drawn are of uniform width and the variable quantity is represented on one of the axes. Also, the measure of the variable is depicted on the other axes. The heights or the lengths of the bars denote value of the variable and these graphs are also used to compare certain quantities. The frequency distribution tables can be easily represented using bar charts which simplify the calculations and understanding of data.

The types of bar charts are as follows:

  1. Vertical bar chart
  2. Horizontal bar chart
  3. Range bar chart

To understand these types, consider the following examples:

Example 1: In a firm of 400 employees, the percentage of monthly salary saved by each employee is given in the following table. Represent it through a bar graph.

Savings (in percentage) Number of Employees(Frequency)
20 105
30 199
40 29
50 73
Total 400

Solution: The given data can be represented as

Bar graph - Vertical

This can be also represented using a horizontal bar graph as follows:

Bar Graph - Horizontal

Example 2: A cosmetic company manufactures 4 different shades of lipstick. The sale for 6 months is shown in the table. Represent it using bar charts.

Month

Sales (in units)
Shade 1 Shade 2 Shade 3 Shade 4
January 4500 1600 4400 3245
February 2870 5645 5675 6754
March 3985 8900 9768 7786
April 6855 8976 9008 8965
May 3200 5678 5643 7865
June 3456 4555 2233 6547

Solution: The graph given below depicts the following data

Bar Graph

Example 3: The variation of temperature in a region during a year is given as follows. Depict it through graph (bar).

Month Temperature
January \(-6^{\circ}C\)
February \(-3.5^{\circ}C\)
March \(-2.7^{\circ}C\)
April \(4^{\circ}C\)
May \(6^{\circ}C\)
June \(12^{\circ}C\)
July \(15^{\circ}C\)
August \(8^{\circ}C\)
September \(7.9^{\circ}C\)
October \(6.4^{\circ}C\)
November \(3.1^{\circ}C\)
December \(-2.5^{\circ}C\)<

Solution: As the temperature in the given table has negative values, it is more convenient to represent such data through horizontal bar graph.

Bar Graph

To learn more about statistics, we suggest you to refer NCERT solutions for Data collection method. To refer Byju’s NCERT solutions for Graphs, click here – Introduction to Graphs


Practise This Question

A bag contains 5 black, 7 red and 3 white balls. A ball is drawn from the bag at random. What is the probability that the ball drawn is either black or white?