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Question
The following table gives the number of branches and number of plants in the garden of a school.
| No. of branches (x) | 2 | 3 | 4 | 5 | 6 |
| No. of plants (f) | 49 | 43 | 57 | 38 | 13 |
Calculate the average number of branches per plant.
Solution
Let the assumed mean (A) = 4.
| No. of branches (x1) | No. of plants (f1) |
u1 = x1 - A x1 - 4 |
f1u1 |
| 2 | 49 | -2 | -98 |
| 3 | 43 | -1 | -43 |
| 4 | 57 | 0 | 0 |
| 5 | 38 | 1 | 28 |
| 6 | 13 | 2 | 85 |
| N = 200 | `sumf_1u_1=-77` |
Average number of branches per plant `=A+(sumf_1u_1)/N`
`=4+(-77)/200`
`=4-77/200`
`=(800-77)/200`
= 3.615
= 3.62(Approx)
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