# Frequency Polygon – Introduction – How to Draw a Frequency Polygon – Steps

Frequency Polygon

Frequency Polygon

A frequency polygon is very similar to a histogram and represents the graphical form of data.

A frequency polygon is used to show a cumulative frequency distribution or compare to sets of data.

In a frequency polygon the number of observations is marked at the the midpoint of the interval with a single point, and a straight line connects each set of point.

**Draw frequency polygons**

First we begin with drawing histograms and follow the following steps:

**Step 1**:- **Choose the class interval of each class and mark the values on horizontal axes.**

**Step 2**:- **Mark the mid value of each interval on the horizontal axes.**

Calculate the class mark for each class interval. The formula for class mark is,

**Class mark = (Upper limit + Lower limit)/2**

**Step 3**:- **Mark the frequency of the class on the vertical axes.**

**Step 4**:- **Corresponding to frequency of each class interval, mark a point at the height in the middle of the class interval. **

**Step 5**:- **Join all the plotted points using a line segment.**

**Step 6**:- **The resulting representation is a frequency polygon.**