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Question
Find the modal and median classes of the following distribution.
| Class | 0 – 20 | 20 – 40 | 40 – 60 | 60 – 80 | 80 – 100 |
| Frequency | 11 | 22 | 19 | 18 | 7 |
Solution
| Class | Frequency | cf |
| 0 – 20 | 11 | 11 |
| 20 – 40 | 22 | 33 |
| 40 – 60 | 19 | 52 |
| 60 – 80 | 13 | 65 |
| 80 – 100 | 7 | 72 |
| `sumf_i` = 72 |
Here, highest frequency is 22
Hence, modal class is 20 – 40
Also, N = `sumf_i` = 72
Now, `N/2 = 72/2` = 36
36 lies in cumulative frequency 52
So, median class is 40 – 60.
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