In the video session “Computing median from histogram” , professor says the exact median cannot be determined if the individual values are not known but the median class can be evaluated. The mid point of the interval would be an approximation for the median.

But in statistics book, there is formula given for continuous data where frequencies are given and not the actual data points which goes by

Median = L+[h/f *(N/2-c)]

Where ‘L’ is the lower limit of the median class

(The median class is one whose cumulative Freq is just greater than N/2)

‘h’ is the class width of the median class

'f ’ is the Freq of median class

‘c’ is the cumulative Freq of the class preceding the median class.

Can this formula not be used. Please clarify