The table below shows the salaries of 280 persons:

Salary (In thousand Rs.) | No. of persons |

5-10 | 49 |

10-15 | 133 |

15-20 | 63 |

20-25 | 15 |

25-30 | 6 |

30-35 | 7 |

35-40 | 4 |

40-45 | 2 |

45-50 | 1 |

Calculate the median salary of the data.

### Answer

Salary (In thousand Rs.) | No. of persons (f) | cf |

5-10 | 49 | 49 |

10-15 | 133 | 182 |

15-20 | 63 | 245 |

20-25 | 15 | 260 |

25-30 | 6 | 266 |

30-35 | 7 | 273 |

35-40 | 4 | 277 |

40-45 | 2 | 279 |

45-50 | 1 | 280 |

Here, N = 280

N/2 = 280/2 = 140

It is less than 182, hence consider 182 cumulative frequency for the median class.

Median class = 10-15

C = 49. f = 133, l = 10, h = (15 - 10) = 5

Now use the formula,

Median = 10 + (140 - 49)/133 × 5

= 10 + 91 × 5/133

= 13.42

Median salary is Rs.13.42 thousand or Rs.13420.