Now we will discuss about the construction of bar graphs or column graph.

In brief let us recall about,** what is bar graph?**

**Bar
graph is the simplest way to represent a data.**

● In consists of rectangular bars of equal width.

● The space between the two

consecutive bars must be the same.

● Bars can be marked both

vertically and horizontally but normally we use vertical

bars.

● The height of bar

represents the frequency of the corresponding observation.

**For
example,** let us observe the following data of the

bar graph.

The following data

gives the information of the number of children involved in different

activities.

Activities |
Dance | Music | Art | Cricket | Football |

No. of Children |
30 | 40 | 25 | 20 | 53 |

**How to Construct a Bar Graph?**

**Steps
in **

**construction**

of bar graphs/column graph:

of bar graphs/column graph:

● On a graph, draw two

lines perpendicular to each other, intersecting at 0.

● The horizontal line is

x-axis and vertical line is y-axis.

● Along the horizontal

axis, choose the uniform width of bars and uniform gap between the

bars and write the names of the data items whose values are to be marked.

● Along the vertical axis,

choose a suitable scale in order to determine the heights of

the bars for the given values. (Frequency is taken along y-axis).

● Calculate the heights of

the bars according to the scale chosen and draw the bars.

Bar graph gives the information of the

number of children involved in different activities.

**Solved examples on ****construction of bar graphs:**

**1.** The percentage of total income spent

under various heads by a family is given below.

Different Heads |
Food | Clothing | Health | Education | House Rent | Miscellaneous |

% Age of TotalNumber |
40% | 10% | 10% | 15% | 20% | 5% |

Represent the above data in the form of bar

graph.

**2.** 150 students of class VI have popular

school subjects as given below:

Subject |
French | English | Maths | Geography | Science |

Number of Students |
30 | 20 | 26 | 38 | 34 |

Draw the column graph/bar graph

representing the above data.

**Solution:**

Take the subjects along **x-axis**, and the number of students

along **y-axis**

Bar graph gives the information of

favourite subjects of 150 students.

**3. **The vehicular traffic

at a busy road crossing in a particular place was recorded on a particular day

from 6am to 2 pm and the data was rounded off to the nearest tens.

Time in Hours |
6 – 7 | 7 – 8 | 8 – 9 | 9 – 10 | 10 – 11 | 11 – 12 | 12 – 1 | 1 – 2 |

Number of Vehicles |
100 | 450 | 1250 | 1050 | 750 | 600 | 550 | 200 |

Bar graph gives the information of number

of vehicles passing through the crossing during different intervals of time.

**● Statistics**

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