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#### Question

The following table gives the life times of 400 neon lamps:-

Life time (in hours) | Number of lamps |

300 - 400 | 14 |

400 - 500 | 56 |

500 - 600 | 60 |

600 - 700 | 86 |

700 - 800 | 74 |

800 - 900 | 62 |

900 - 1000 | 48 |

(i) Represent the given information with the help of a histogram.

(ii) How many lamps have a life time of more than 700 hours?

#### Solution

#### Similar questions

The runs scored by two teams A and B on the first 60 balls in a cricket match are given below:-

Number of balls | Team A | Team B |

1 - 6 | 2 | 5 |

7 - 12 | 1 | 6 |

13 - 18 | 8 | 2 |

19 - 24 | 9 | 10 |

25 - 30 | 4 | 5 |

31 - 36 | 5 | 6 |

37 - 42 | 6 | 3 |

43 - 48 | 10 | 4 |

49 - 54 | 6 | 8 |

55 - 60 | 2 | 10 |

Represent the data of both the teams on the same graph by frequency polygons.

[**Hint** :- First make the class intervals continuous.]

The length of 40 leaves of a plant are measured correct to one millimetre, and the obtained data is represented in the following table:-

Length (in mm) | Number of leaves |

118 - 126 | 3 |

127 - 135 | 5 |

136 - 144 | 9 |

145 - 153 | 12 |

154 - 162 | 5 |

163 - 171 | 4 |

172 - 180 | 2 |

(i) Draw a histogram to represent the given data. [Hint: First make the class intervals continuous]

(ii) Is there any other suitable graphical representation for the same data?

(iii) Is it correct to conclude that the maximum number of leaves are 153 mm long? Why?

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.

The following table gives the distribution of students of two sections according to the mark obtained by them:-

Section A | Section B | ||

Marks | Frequency | Marks | Frequency |

0 - 10 | 3 | 0 - 10 | 5 |

10 - 20 | 9 | 10 - 20 | 19 |

20 - 30 | 17 | 20 - 30 | 15 |

30 - 40 | 12 | 30 - 40 | 10 |

40 - 50 | 9 | 40 - 50 | 1 |

Represent the marks of the students of both the sections on the same graph by two frequency polygons. From the two polygons compare the performance of the two sections.

100 surnames were randomly picked up from a local telephone directory and a frequency distribution of the number of letters in the English alphabet in the surnames was found as follows:-

Number of letters | Number of surnames |

1 - 4 | 6 |

4 - 6 | 30 |

6 - 8 | 44 |

8 - 12 | 16 |

12 - 20 | 4 |

(i) Draw a histogram to depict the given information.

(ii) Write the class interval in which the maximum number of surnames lie.