Question 42
The length in km (rounded to nearest hundred) of some major rivers fo India is given below:
$\begin{array}{cc}\text{River}& \text{Length(in km)}\\ \text{Narmada}& 1300\\ \text{Mahanadi}& 900\\ \text{Brahmaputra}& 2900\\ \text{Ganga}& 2500\\ \text{Kaveri}& 800\\ \text{Krishna}& 1300\end{array}$
Draw a bar graph to represent the above information.

A Bar Graph (also called Bar Chart) is a graphical display of data using bars of different heights.

In order to construct a bar graph representing the above data, we follow the following steps:
$StepI$ Take a graph paper and draw two mutually perpendicular lines $OX$ and $OY$ let $OX$as the horizontal axis and $OY$ as the vertical axis.
$StepII$ Along $OX,$ mark rivers name and along $OY$, mark length in kilometres.
$StepIII$ Along $OX$ choose the uniform equal width fo the bars and the uniform gap between them according to the space available for the graph.
$StepIV$ Choose a suitable scale to determine the heights of the bars, according to the availability of space, here, we choose 1 unit length represents $200$ km.
$StepV$ Calculate the height of bars for various rivers are as follows.

$\begin{array}{cc}\text{Name of the River}& \text{Height of bars}\\ \text{Narmada}& \frac{1300}{200}=6.5\text{units}\\ \text{Mahanadi}& \frac{900}{200}=4.5\text{units}\\ \text{Brahmaputra}& \frac{2900}{200}=14.5\text{units}\\ \text{Ganga}& \frac{2500}{200}=12.5\text{units}\\ \text{Kaveri}& \frac{800}{200}=4\text{units}\\ \text{Krishna}& \frac{1300}{200}=6.5\text{units}\end{array}$

Hence the required bar graph of given data is shown below