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Question
If the mean of the following data is 20.6. Find the value of p.
| x | 10 | 15 | P | 25 | 35 |
| f | 3 | 10 | 25 | 7 | 5 |
Solution
| x | f | fx |
| 10 | 3 | 30 |
| 5 | 10 | 150 |
| P | 25 | 25P |
| 25 | 7 | 175 |
| 35 | 5 | 175 |
| N = 50 | `sum`fx = 530 + 25P |
Given
⇒ Mean = 20.6
`rArr(sumfx)/N=20.6`
`rArr(530+25P)/50=20.6`
⇒ 25P = 20.6(50) - 530
`rArrP=500/25`
⇒ P = 20
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