Median of Grouped Data. Median:It is a measure of central tendency which gives the value of the middle-most observation in the data. Method for finding of median of Ungrouped Data. If $n$ is the number of ungrouped data, arrange the data in ascending order. Case 1: If $n$ is odd , then median = $({n+1}/2)^{th}$ observation Case 2: If $n$ is even , then median = average of $({n+1}/2)^{th}$ and $({n}/2)^{th}$ observation Method for finding of median of Grouped Data. Median = $l$ + $({n/2-cf}/{f})$ $×h$ where $l$ = lower limit of median class, $n$ = number of observations, $cf$ = cumulative frequency of class preceding the median class, $f$ = frequency of median class, $h$ = class size (assuming class size to be equal).