The amounts (in ₹ lakh) of 80 loans sanctioned by a bank branch, grouped in unequal classes:
0-5 -> 9, 5-10 -> 13, 10-20 -> 24, 20-40 -> 20, 40-80 -> 14.
Find the median loan amount (₹ lakh).

Cumulative: 9, 22, 46, 66, 80, so $n=80$ and $\frac{n}{2}=40$. The first cf to reach 40 is 46, so the median class is 10-20 with $l=10$, cf = 22, $f=24$ and its own width $h=10$. Median = $10+\left(\frac{40-22}{24}\right)\times 10=10+7.5=17.5$, i.e. ₹17.5 lakh. 13.75 borrows $h=5$ from the first classes and 25 borrows $h=20$ from the next class — with unequal widths you must use the median class's own width. 15 is the class mark of 10-20.