# Ex.14.3 Q2 Statistics Solution - NCERT Maths Class 9

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## Question

The following data on the number of girls (to the nearest ten) per thousand boys in different sections of Indian society is given below.

Section |
Number of girls per thousand boys |

Scheduled Caste (SC) | \(940\) |

Scheduled Tribe (ST) | \(970\) |

Non SC/ST | \(920\) |

Backward districts | \(950\) |

Non-backward districts | \(920\) |

Rural | \(930\) |

Urban | \(910\) |

(i) Represent the information above by a bar graph.

(ii) In the classroom discuss what conclusions can be arrived at from the graph.

Video Solution

Statistics

Ex exercise-14-3 | Question 2

## Text Solution

**What is known? **

The number of girls (to the nearest ten) per thousand boys in different sections of Indian society is given

**Unknown:**

- Graphical representation of the given information.
- Conclusions that can be arrived from the graph.

**Reasoning:**

The above data can be represented graphically using a bar graph as below:

- Represent the ‘section’ on the \(x\)-axis and ‘number of girls per thousand boys on the \(y\)-axis.
- We will select a scale of \(1\,\rm unit = 100\) girls for \(y\)-axis as the max value did not exceed low.
- We will maintain equal width for all the bars in \(x\)-axis and also maintain equal gaps in between the bars.

**Steps:**

It can be observed from the graph that:

- The number of girls per thousand boys is highest for \(ST\) category.
- The number of girls per thousand boys is lowest for urban category.
- The ‘number of given / \(1000\)’ boys are higher in rural area than in urban.
- The ‘number of given / \(1000\)’ boys are also higher in backward districts them in non-backward districts.

Point to note:

- The variations in values occur mostly in the range of \(900-970.\)
- The values are same until \(900.\)
- Hence to make the variations more visible and distinct and for a better study of the graph, we can keep the starting value on the \(y\)-axis as ‘\(900\)’ with a scale of \(1\,\rm unit\) as ‘\(10\)’ and re construct the graph as shown below:

Number of girls / thousands of boys

As you can see, the above graph shows a clear picture of the data and helps us to arrive at conclusions easily.