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प्रश्न
Find the mean of the following frequency distribution:
| Class Interval | Frequency |
| 0 - 50 | 4 |
| 50 - 100 | 8 |
| 100 - 150 | 16 |
| 150 - 200 | 13 |
| 200 - 250 | 6 |
| 250 - 300 | 3 |
उत्तर
| Class - Interval | (x) | (f) | (fx) |
| 0 - 50 | 25 | 4 | 100 |
| 50 - 100 | 75 | 8 | 600 |
| 100 - 150 | 125 | 16 | 2,000 |
| 150 - 200 | 175 | 13 | 2,275 |
| 200 - 250 | 225 | 6 | 1,350 |
| 250 - 300 | 275 | 3 | 825 |
| `sumf` = 50 | `sumfx` = 7,150 |
∴ Mean = `(sumfx)/(sumf)`
= `(7150)/(50)`
= 143.
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