The following data give the distribution of heights of students:
 

The median of the distribution is 

Arranging the data in ascending order of magnitude, we obtain
 

Here, the total number of items is 41, i.e., an odd number. 

$\text{ Hence, the median is }\frac{41+1}{2}\text{ th i.e., }21\text{ st item. }$

From cumulative frequency table, we find that the median, i.e. 2lst item is 155. (All items from l6th to 22nd are equal, each 155).