Question

The following table gives the distribution of students of two sections according to the marks obtained by him: Section A	Section B
Marks	Frequency
0 − 10	3
10 − 20	9
20 − 30	17
30 − 40	12
40 − 50	9

Represent the marks of the students of both the sections on the same graph by two frequency polygons. From the two polygons compare the performance of the two sections.

Answer 1

We can find the class marks of the given class intervals by using the following formula.

$\text{ Class mark} =\frac{\text{ 𝑈𝑝𝑝𝑒𝑟 𝑐𝑙𝑎𝑠𝑠 𝑙𝑖𝑚𝑖𝑡+𝐿𝑜𝑤𝑒𝑟 𝑐𝑙𝑎𝑠𝑠 𝑙𝑖𝑚𝑖𝑡 }}{2}$

Section A	Section B
Marks	Class marks
0 − 10	5
10 − 20	15
20 − 30	25
30 − 40	35
40 − 50	45

We plot the class-mark on x-axis and number of students on y-axis.

From the above graph, we observed that students of section A performed better because as we move right on x-axis the number of students are spread widely over greater marks as compared to the students of section A.