Question

The mid-value of a class interval is 42. If the class-size is 10, find the upper and lower limits of the class.

Answer 1

$\Rightarrow$ Let upper limit and lower limit be $x$ and $y$

$\Rightarrow$ $\frac{x+y}{2}=42$ [ Given ]

$\therefore$ $x+y=84$ ------ ( 1 )

Now, according to the question,

$\Rightarrow$ $x-y=10$ ------ ( 2 )

Adding equation ( 1 ) and ( 2 ) we get,

$2x=94$

$\therefore$ $x=47$

And $47-y=10$

$\therefore$ $y=37$

$\therefore$ Required class interval $=37-47$