Question

Draw histogram and frequency polygon.

Max. temp.	24 – 28	28 – 32	32 – 36	36 – 40	40 – 44
No. of towns	4	5	7	8	6

Answer 1

1. Prepare data table

To draw the frequency polygon, calculate the class mark (midpoint) for each class interval using the formula:

Class Mark = `("Lower Limit" + "Upper Limit")/2`

Additionally, create two imaginary classes with a frequency of 0 at both ends (20 – 24 and 44 – 48) to anchor the polygon to the horizontal axis.

Max.Temperature  (C°)	Class Mark (Midpoint)	No. of Towns (Frequency)	Points for Polygon (x, y)
20 – 24 (Imaginary)	22	0	(22, 0)
24 – 28	26	4	(26, 4)
28 – 32	30	5	(30, 5)
32 – 36	34	7	(34, 7)
36 – 40	38	8	(38, 8)
40 – 44	42	6	(42, 6)
44 – 48 (Imaginary)	46	0	(46, 0)

2. Draw histogram

3. Plot frequency polygon

Identify coordinates: Locate the center top point of each histogram bar, which corresponds to the coordinates (Class Mark, Frequency).

Connect the points: Join the consecutive points with straight line segments. 

Close the polygon: Extend the lines to the imaginary points (22, 0) and (46, 0) on the X-axis to complete a closed geometric polygon figure.