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.

Answer 1

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)