A farmer collected data on the annual rainfall, x cm, and the annual yield of peas, p tonnes per acre - Edexcel - A-Level Maths Statistics - Question 4 - 2011 - Paper 1
Question 4
A farmer collected data on the annual rainfall, x cm, and the annual yield of peas, p tonnes per acre.
The data for annual rainfall was coded using v = \frac{x - 5}... show full transcript
Worked Solution & Example Answer:A farmer collected data on the annual rainfall, x cm, and the annual yield of peas, p tonnes per acre - Edexcel - A-Level Maths Statistics - Question 4 - 2011 - Paper 1
Step 1
Find the equation of the regression line of p on v in the form p = a + bv.
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Answer
To find the regression line of p on v, we need the values of the regression coefficients a and b.
Calculate the slope, b:
b=SpmSp=1.1681.688≈1.44
Calculate the intercept, a:
a=p−b⋅v=3.22−1.44⋅4.42≈3.22−6.37≈−3.15
The equation of the regression line is:
p=−3.15+1.44v
Step 2
Using your regression line estimate the annual yield of peas per acre when the annual rainfall is 85 cm.
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Answer
First, we need to code the value of x = 85 cm into v:
v=1085−5=1080=8
Now we substitute v into the regression equation:
p=−3.15+1.44⋅8\n=−3.15+11.52\n=8.37
Therefore, the estimated annual yield of peas per acre when the annual rainfall is 85 cm is approximately 8.37 tonnes.