Question

plz help me to solve this question and plz give me the correct answer ​

Answer 1

Answer:

Class 30 to 40 - 10 to 30

Class 40 to 50 - 30 to 45

......

Answer 2

Class | Frequency
30 - 40 | 20
40 - 50 | 40
50 - 60 | 50
60 - 70 | 60
70 - 80 | 35
80 - 90 | 15

Explanation:
In the co-ordinates (x,y), the ‘y’ is always the frequency and the ‘x’ is always the class mark.
Here, the frequency = no. of students.

Note: Class Mark is the no. which we obtain after dividing the sum of the lower class limit and the upper class limit of a class by 2