# 4

A pediatrician has obtained the following table which represents the number of children who begin to walk for the first time at different ages:

Months | Children |

9 | 1 |

10 | 4 |

11 | 9 |

12 | 16 |

13 | 11 |

14 | 8 |

15 | 1 |

1. Draw the respective frequency polygon.

2. Calculate the mode, median, mean and variance.

#### Frequency Polygon

x_{i} |
f_{i} |
N_{i} |
x_{i} · f_{i} |
x²_{i} · f_{i} |

9 | 1 | 1 | 9 | 81 |

10 | 4 | 5 | 40 | 400 |

11 | 9 | 14 | 99 | 1089 |

12 | 16 | 30 | 192 | 2304 |

13 | 11 | 41 | 143 | 1859 |

14 | 8 | 49 | 112 | 1568 |

15 | 1 | 50 | 15 | 225 |

50 | 610 | 7526 |

#### Mode

Mo = 12

#### Median

50/2 = 25 Me = 12

#### Arithmetic Mean

#### Variance

Subject

Site