#### notes

The information in a frequency table can be presented in various ways. We have studied a histogram. A frequency polygon is another way of presentation.

Let us study two methods of drawing a frequency polygon.

(1) With the help of a histogram (2) Without the help of a histogram.

**(1)** We shall use the histogram in figure to learn the method of drawing a frequency polygon.

1. Mark the mid - point of upper side of each rectangle in the histogram.

2. Assume that a rectangle of zero height exists preceeding the first rectangle and mark its mid - point. Similarly, assume a rectangle succeeding the last rectangle and mark its mid -point.

3. Join all mid - points in order by line segments.

4. The closed figure so obtained is the frequency polygon.

**(2)** Observe the following table. It shows how the coordinates of points are decided to draw a frequency polygon, without drawing a histogram.

The points corresponding to the coordinates in the fifth column are plotted. Joining them in order by line segments, we get a frequency polygon. The polygon is shown in figure . Observe it.

#### Related QuestionsVIEW ALL [1]

Draw a frequency polygon from the information given in the following table.

Age of blood donar (Years) | No. of blood donars |

Less than 20 | 0 |

Less than 25 | 30 |

75Less than 30 | 75 |

165Less than 35 | 127 |

Less than 40 | 165 |

Less than 45 | 185 |

Less than 50 | 197 |