Question

If the class mark of a class interval is 8.5.the class size is 5.find the class limits of the corresponding class interval.

Answer 1

Given that
$\frac{x + y}{2} = 8.5 \\ x + y = 17$
And
$x - y = 5$
This gives
$2x = 22 \\ x = 11 \\ y = 6$