question number 3. determine the correlation coefficient for the data shown in this table: \n| y | x…

question number 3. determine the correlation coefficient for the data shown in this table: \n| y | x |\n|----|----| \n| 22 | 2 |\n| 29 | 4 |\n| 28 | 10 |\n| 40 | 15 |\n| 34 | 13 |\n| 43 | 16 |\no 0.8332\no 0.4564\no -0.9128\no 0.9128\no -0.8332\no none of the above
Answer
Explanation:
Step1: Recall correlation - coefficient formula
The Pearson correlation coefficient $r$ is given by the formula: [r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^{2}-(\sum x)^{2}][n\sum y^{2}-(\sum y)^{2}]}}] First, calculate the necessary sums: Let $n = 6$.
| $y$ | $x$ | $xy$ | $x^{2}$ | $y^{2}$ |
|---|---|---|---|---|
| 22 | 2 | 44 | 4 | 484 |
| 29 | 4 | 116 | 16 | 841 |
| 28 | 10 | 280 | 100 | 784 |
| 40 | 15 | 600 | 225 | 1600 |
| 34 | 13 | 442 | 169 | 1156 |
| 43 | 16 | 688 | 256 | 1849 |
$\sum x=2 + 4+10 + 15+13+16=60$ $\sum y=22 + 29+28+40+34+43=196$ $\sum xy=44 + 116+280+600+442+688=2170$ $\sum x^{2}=4 + 16+100+225+169+256=770$ $\sum y^{2}=484+841+784+1600+1156+1849=6714$
Step2: Substitute into the formula
[n(\sum xy)-(\sum x)(\sum y)=6\times2170-60\times196] [=13020 - 11760=1260]
[n\sum x^{2}-(\sum x)^{2}=6\times770-60^{2}] [=4620 - 3600 = 1020]
[n\sum y^{2}-(\sum y)^{2}=6\times6714-196^{2}] [=40284-38416 = 1868]
[r=\frac{1260}{\sqrt{1020\times1868}}] [=\frac{1260}{\sqrt{1905360}}] [=\frac{1260}{1380.3477}\approx0.9128]
Answer:
0.9128