Question

7. The classes which are in the form of 30-40, 40-50, 50-60 ... are called
classes.
4 is​

Answer 1

Answer:

Class−interval Class−mark Frequency

30−40 35 11

40−50 45 12

50−60 55 13

60−70 65 9

70−80 75 4

⇒ The above image shows combined histogram and frequency polygon.

solution

Answer 2

Answer:

It should be( class mark ) I think .