Question

A farmer assumes that there is a linear relationship between the amount of fertilizers supplied to potato plants and the subsequent yield of potatoes obtained.

eight potato plants, of the same variety, were selected at random and treated, weekly, with a solution in which x grams of fertilizer was dissolved in a fixed quantity of water. The yield, y kilograms, of potatoes was recorded.

Plant	A	B	C	D	E	F	G	H
x	1.0	1.5	2.0	2.5	3.0	3.5	4.0	4.5
y	3.9	4.4	5.8	6.6	7.0	7.1	7.3	7.7

(a) Plot a scatter diagram of yield, Plot a scatter diagram of yield, y, against amount of fertilizer, x.

(b) Calculate the equation of the square regression line of y on x.

(c) Estimate the yield of a plant treated, weekly with 3.2 grams of fertilizer.

Answer 1