The formulae for calculating the median if individual observations are given will be.
Median is the middle most value of a series. So when the series has odd number of elements then median can be calculated easily but when the series has even number of elements then the series has two middle values, so median is calculated by taking out the average of both the value.
The series is first arranged into either ascending or descending order. The formula to calculate median = (N+1) /2 th term of the series in case odd numbers of data and median = N/2th term of the series in case even number of data where N is the number of observation in the series.