A biologist assumes that there is a linear relationship between the amount of fertilizer supplied to tomato plant and the subsequent yield of tomatoes obtained. Eight(8) tomato plants of the same variety, were selected at random and treated, weekly, with a solution in which x grams(g) of fertilizer was dissolved in a fixed quantity of water. The yield y kilograms (kg) of tomatoes was recorded as follows.
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
(i). Plot a scatterplot of yield, y against amount of fertilizer, x. ( 3 points)
(ii). Calculate the equation of the least square regression line of y on x. ( 8 points)
(iii). Estimate the yield of a plant treated, weekly, with a 3.2 grams of fertilizer.
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
(i). Plot a scatterplot of yield, y against amount of fertilizer, x. ( 3 points)
(ii). Calculate the equation of the least square regression line of y on x. ( 8 points)
(iii). Estimate the yield of a plant treated, weekly, with a 3.2 grams of fertilizer.
