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प्रश्न
If the mean of the following distribution is 3, find the value of p.
| x | 1 | 2 | 3 | 5 | p + 4 |
| f | 9 | 6 | 9 | 3 | 6 |
उत्तर
We have,
| x | f | fx |
| 1 | 9 | 9 |
| 2 | 6 | 12 |
| 3 | 9 | 27 |
| 5 | 3 | 15 |
| p + 4 | 6 | 6p + 24 |
| `sumf = 33` | `sumfx = 6p + 87` |
Now, Mean = `(sumfx)/(sumf)`
`=> 3 = (6p + 87)/33`
`=>` 99 = 6p + 87
`=>` 6p = 12
`=>` p = 2
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