Question

5. If the class marks of a frequency, distribution are 10, 15 and 20, then which class interval coresponds to the class mark 157​

Answer 1

Answer:

Correct option is

B

17.5,22.5

Class marks are: 15,20,25,...

Lower limit of class 20 is mean of 15 and 20=  

2

15+20

​

=17.5

Upper limit of class 20 is the mean of 20 and 25=  

2

20+25

​

=22.5

20 is the class mark for the class interval 17.5−22.5