Write the median class of the following distribution:
Classes: | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 | 60-70 |
Frequency: | 4 | 4 | 8 | 10 | 12 | 8 | 4 |
First, we prepare the cumulative frequency table for above data
Class | Frequency | Cumulative Frequency |
0-10 10-20 20-30 30-40 40-50 50-60 60-70 | 4 4 8 10 12 8 4 | 4 8 16 26 38 46 50 |
N = 50- |
We know that median class of a data is the class-interval corresponding to cumulative frequency just greater than
Where,
N = sum of all frequencies
As N = 25 therefore
And
Cumulative frequency just greater than 25 is 26 which lies corresponding to class 30-40
Hence, 30-40 is median class.