Question

The following data were acquired in a study of diabetic patients.

Ages	10-20	20-30	30-40	40-50	50-60
No. of patients	7	11	19	9	1

Construct a frequency polygon for the data given.

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

We have to first calculate the class marks of the all the classes.

Class intervals (Ages)	Frequency (No. of patients)	Class marks	Points
0-10	0	5	(5,0)
10-20	7	15	(15,7)
20-30	11	25	(25,11)
30-40	19	35	(35,19)
40-50	9	45	(45,9)
50-60	1	55	(55,1)
60-70	0	65	(65,0)

Take suitable scale,
On X-axis 1 cm = 1 class interval
On Y-axis 1 cm = 2 patients

Take class marks on X-axis and frequency on Y-axis.
Now plot the points in the graph.