Question

class mark of a particular class is 10.5 and class size is 7. Find class interval

Answer 1

Let upper and lower limit be x and y respectively

Class mark=10.5
(Lower+Upper) limit/2=10.5
(Lower+Upper) limit= 10.5x2
Lower limit + Upper Limit= 21
Upper+lower limit= 21
x+y=21 ........(1)

Class size= 7
Upper limit - lower limit = 7
x-y=7 .........(2)

Now, on comparing (1)&(2)
we get, x+y = 21
x-y = 7

So, x+y = 21
-x+y= -7
2y=14
y=7
So lower limit = 7
Now put the value of y in (2)
And, x-y = 7
x-7= 7
x=7+7
x=14

Therefore, Upper limit= 14
And, Lower limit= 7

Answer 2

Hi there !

Ÿour Answer =>

Let upper and lower limit be x and y respectively

Class mark=10.5

(Lower+Upper) limit/2=10.5

(Lower+Upper) limit= 10.5x2

Lower limit + Upper Limit= 21

Upper+lower limit= 21

x+y=21 ........(1)

Class size= 7

Upper limit - lower limit = 7

x-y=7 .........(2)

Now, on comparing (1)&(2)

we get, x+y = 21

x-y = 7

So, x+y = 21

-x+y= -7

2y=14

y=7

So lower limit = 7

Now put the value of y in (2)

And, x-y = 7

x-7= 7

x=7+7

x=14

Therefore, Upper limit= 14

And, Lower limit= 7

Be Brainly!