Answer:
Option: A is the correct answer.
A. -0.903
Step-by-step explanation:
The formula to calculate correlation coefficient r is given by:
[tex]r=\dfrac{n\sum xy-(\sum x)(\sum y)}{\sqrt{n(\sum x^2)-(\sum x)^2}\sqrt{n(\sum y^2)-(\sum y)^2}}[/tex]
x y xy x² y²
4 23 92 16 529
5 12 60 25 144
8 10 80 64 100
9 9 81 81 81
13 2 26 169 4
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∑ 39 56 339 355 858
Also n=5 ( as there are 5 data points )
Hence, we get:
[tex]r=\dfrac{5\times 339-39\times 56}{\sqrt{5\times 355-(39)^2}\times \sqrt{5\times 858-(56)^2}}\\\\\\r=\dfrac{-489}{\sqrt{254}\times \sqrt{1154}}\\[/tex]
[tex]r=-\dfrac{489}{541.40188}=-0.9032[/tex]
Hence, the r-value of the following data, to three decimal places is:
A. -0.932
