If the class marks of a class interval is 8.5 . . .

Questions : If the class marks of a class interval is 8.5. The class size is 5, then the class limits of the corresponding class interval is 

a) 6.5-11.5

b) 6-11

c) 5.5-10.5

d) 7-12

Doubt by Lakshay 

Solution : Coming Soon

Class Marks (x) = 8.5

Class size (h) = 5

Lower Limit = ?

Upper Limit = ?

We know, 
Lower Limit (LL)  

= Class Marks (x) - Class Size (h)/2

Upper Limit (UL)  

= Class Marks (x) + Class Size (h)/2

So 

Lower Limit 

= x-h/2

= 8.5-5/2

= 8.5-2.5

= 6

Upper Limit 
= x+h/2

= 8.5+2.5

= 11

The required class interval is 6-11

Hence, b) would be the correct option.