Two sections of 40 students each sit the same test.
Section A: 0-20 -> 6, 20-40 -> 12, 40-60 -> 8, 60-80 -> 14.
Section B: 0-20 -> 4, 20-40 -> 12, 40-60 -> 16, 60-80 -> 8.
What can you say about their medians?

Section A: cumulative 6, 18, 26, 40, so $\frac{n}{2}=20$, median class 40-60 with $l=40,cf=18,f=8,h=20$, and Median = $40+\frac{20-18}{8}\times 20=45$. Section B: cumulative 4, 16, 32, 40, median class 40-60 with $cf=16,f=16$, and Median = $40+\frac{20-16}{16}\times 20=45$. The medians are identical. A median only locates the middle and says nothing about spread — A has 20 students in the two extreme classes against B's 12. A bigger top-class frequency does not by itself lift the median, and a bigger median-class frequency does not by itself lower it: what matters is the single ratio $\frac{n/2-cf}{f}$, which is $\frac{1}{4}$ for both.