Consider the following frequency distribution

The upper limit of the median class is

Given, classes are not continuous, so we make continuous by subtracting 0.5 from lower limit and adding 0.5 to upper limit of each class.

Here, N/2 = 57/2 = 28.5

which lies in the interval 11.5 - 17.5.

Hence, the upper limit is 17.5.