Question

class mark of a particular class is 10.5 and the class size is 7 find is class interval

Answer 1

here.....

let the lower limit & upper limit be x & y respectively.

Class mark=10.5
x+y÷2=10.5
x+y=10.5×2
x+y=21............................(1)

The class size is 7.
so,
y-x=7
-x+y=7....................................(2)

[adding (1) & (2)]

2y=28
y=28/2
y=14

substitute y=14 in equation no. 1

x+y=21
x+14=21
x=21-14
x=7

so,
x=7 & y=14

The lower limit is 7 & upper limit is 14.

The class is 7-14

hope this helps !!! #