The calculation of median involves two basic steps

 

(i)             the location of the middle item and

(ii)             finding out its value.

The middle item in series of individual observations and also in a discrete series is ((n+1)/2) item, where n is the total number of observations. In case of a continuous series (n/2)th item is the middle item of the series.
Once the middle item is located its values has to be found out. In a series of individual observations, if the total number of items is an odd figure, the value of the middle item is the median value. If the number of items is even the median value is the average of the two items in the centre of the distribution.