Here, it can be observed that the data has class intervals of varying width. The proportion of children per 1 year interval can be calculated as follows.

Age (in years) |
Frequency (Number of children0 |
Width of class |
Length of rectangle |

1-2 |
5 |
1 |
5 x 1/1 = 5 |

2-3 |
3 |
1 |
3 x 1/1 = 3 |

3-5 |
6 |
2 |
6 x 1/2 =3 |

5-7 |
12 |
2 |
12 x 1/2 = 6 |

7-10 |
9 |
3 |
9 x 1/3 = 3 |

10-15 |
10 |
5 |
10 x 1/5 = 2 |

15-17 |
4 |
2 |
4 x 1/2 = 2 |

Taking the age of children on x-axis and proportion of children per 1 year interval on y-axis, the histogram can be drawn as follows.