Question

class mark of particular class is9.5 and class size is 6 then class interval

Answer 1

Class mark = 9.5

=> Upper limit + Lower limit / 2 = 9.5

=> u + l = 19 -------(1)

Class mark = 6

=> u - l = 6 --------(2)

On adding equation 1 and 2, we get

2u = 25

=> u = 12.5

l = 6.5

Class interval is ( 6.5 - 12.5)

Answer 2

Answer:

Let the a be the lower limit of the class interval

Class size of the class interval =3

∴ Upper limit of the class interval=a+3

Class mark=6.5

∴

2

a+a+3

=6.5

⇒2a+3=6,5×2

⇒2a=13−3

⇒2a=10⇒a=

2

10

=5

∴a+3=5+3=8

Hence class interval= 5−8

(or)

6.5 -12.5