# CBSE Class 10-Mathematics: Chapter – 14 Statistics Part 15 (For CBSE, ICSE, IAS, NET, NRA 2022)

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**Question 11**:

Following table shows the daily pocket allowances given to the children of a multi-story building. The mean of the pocket allowances is . Find out the missing frequency.

Class Interval | |||||||

Frequency |

**Answer**:

Let the missing frequency , we have

Class interval | Mid-value | |||

11 - 13 | 3 | 12 | -3 | -9 |

13 - 15 | 6 | 14 | -2 | -12 |

15 - 17 | 9 | 16 | -1 | -9 |

17 - 19 | 13 | 18 | 0 | 0 |

19 - 21 | f | 20 | 1 | F |

21 - 32 | 5 | 22 | 2 | 10 |

23 - 25 | 4 | 24 | 3 | 12 |

Let assumed mean , Here

We know that mean

Hence, missing frequency

**Question 12**:

A survey regarding the heights (in cm) of girls of Class of a school was conducted and the following data was obtained. Find the median height.

Height (in cm) | No. of girls |

Less than 140 | |

Less than 145 | |

Less than 150 | |

Less than 155 | |

Less than 160 | |

Less than 165 |

**Answer**:

We have,

Class Intervals | Frequency (f) | C. F |

Below | ||

Here, which is in the class

Here,

Median height of the girls