how to find median in unequal class interval

The presence of unequal class intervals does not pose any problem for the calculation of median. That is, the calculation of median remains the same as in equal class intervals.  Median is calculated using the following formula.

Here,

l₁ represents lower limit of median class

c.f. represents cumulative frequency of the class preceding the median class

f represents frequency of median class

i represents the size of median class interval