Respuesta :
Correlation simply describes the association between two variables.
- The calculated correlation is -0.8110
- The software result is -0.8111
Given that:
[tex]x:\{26.7, 26.7, 26.6, 26.6, 26.6, 26.6, 26.5, 26.5, 26.3,26.3, 26.1,26.1\}[/tex]
[tex]y = \{0.85, 0.85, 0.85, 0.85, 0.79, 0.79, 0.86, 0.86, 0.89, 0.89, 0.92, 0.92\}[/tex]
(a) Calculate the correlation (r), manually
Start by calculating the mean of x and y
[tex]\bar x = \frac{\sum x}{n}[/tex]
[tex]\bar x = \frac{26.7+26.7+26.6+26.6+26.6+26.6+26.5+26.5+26.3+26.3+26.1+26.1}{12}[/tex]
[tex]\bar x = \frac{317.6}{12}[/tex]
[tex]\bar x = 26.47[/tex]
[tex]\bar y = \frac{\sum y}{n}[/tex]
[tex]\bar y = \frac{0.85+ 0.85+0.85+ 0.85+ 0.79+0.79+ 0.86+ 0.86+ 0.89+ 0.89+ 0.92+ 0.92}{12}[/tex]
[tex]\bar y = \frac{10.32}{12}[/tex]
[tex]\bar y = 0.86[/tex]
Calculate square of x deviation [tex]SS_x[/tex]
[tex]SS_x = \sum(x - \bar x)^2[/tex]
[tex]SS_x = (26.7 - 26.47)^2+.....+(26.1 - 26.47)^2+(26.1 - 26.47)^2[/tex]
[tex]SS_x = 0.5068[/tex]
Calculate square of y deviation [tex]SS_y[/tex]
[tex]SS_y = \sum(y - \bar y)^2[/tex]
[tex]SS_y = (0.85 - 0.86)^2 + (0.85- 0.86)^2 +........+ (0.92- 0.86)^2[/tex]
[tex]SS_y = 0.0192[/tex]
Calculate the sum of product of x and y deviation [tex]\sum(x - \bar x) \times \sum(y - \bar y)[/tex]
[tex]\sum(x - \bar x) \times \sum(y - \bar y) = (26.7-26.47) \times (0.85 - 0.86) + (26.7-26.47) \times (0.85- 0.86) + ......+(26.1-26.47) \times (0.92- 0.86)[/tex]
[tex]\sum(x - \bar x) \times \sum(y - \bar y) = -0.08[/tex]
The coefficient (r) is then calculated as follows:
[tex]r = \frac{\sum(x - \bar x) \times \sum(y - \bar y)}{\sqrt{SS_x \times SS_y}}[/tex]
[tex]r = \frac{-0.08}{\sqrt{0.5068 \times 0.0192}}[/tex]
[tex]r = \frac{-0.08}{\sqrt{0.00973056}}[/tex]
[tex]r = \frac{-0.08}{0.0986436009}[/tex]
[tex]r = -0.8110[/tex]
(b) Calculate the correlation (r), using a software
Using a software,
[tex]r = -0.8111[/tex]
See attachment for the results
Hence, the correlation is -0.8110
Read more about correlation at:
https://brainly.com/question/20804169
