Question

Class interval 10-15,15-20,20-25,25-30,30-35
Frequency 5,7,4,6,8
The class mark for the second class is
A) 27.5
B) 17.5
C) 12.5
D) 32.5

Answer 1

Answer:

Class mark=Upper limit+ lower limit/2

Therefore class mark=15+20/2=17.5.(B).