# Statistics

## Exercise 14.3

### Part 2

Question 4: 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.

**Answer:**

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

**Answer:** Frequency Polygon

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

**Answer:** No, because the data in a particular row shows a range rather than a single number.

Question 5: 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.

**Answer:**

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

**Answer:** 184

Question 6: The following table gives the distribution of students of two sections according to the marks 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.

**Answer:**