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Question
Write the median class of the following distribution:
| Class | 0 – 10 | 10 -20 | 20- 30 | 30- 40 | 40-50 | 50- 60 | 60- 70 |
| Frequency | 4 | 4 | 8 | 10 | 12 | 8 | 4 |
Solution
To find median let us put the data in the table given below:
| Class | Frequency` (f_i)` | Cumulative frequency (cf) |
| 0-10 | 4 | 4 |
| 10-20 | 4 | 8 |
| 20-30 | 8 | 16 |
| 30-40 | 10 | 26 |
| 40-50 | 12 | 38 |
| 50-60 | 8 | 46 |
| 60-70 | 4 | 50 |
| Total | `N=Σf_i=50` |
Now, `N=50⟹N/2=25`
The cumulative frequency just greater than 25 is 26, and the corresponding class is 30-40.
Thus, the median class is 30-40.
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