Enter two data sets and this calculator will find the equation of the regression line and correlation coefficient. The calculator will generate a step by step explanation along with the graphic representation of the data sets and regression line.
solution
You entered the following data:
$$\begin{array}{c|cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc}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end{array}$$The equation of the regression line is:
$$y~=~3693 ~-~ 4.258 \cdot x$$The graph of the regression line is:
explanation
We will find an equation of the regression line in 4 steps.
Step 1: Find $X \cdot Y$ and $X^2$ as it was done in the table below.
$X$ | $Y$ | $X\cdot Y$ | $X \cdot X$ |
18 | 5290 | 95220 | 324 |
24 | 5109 | 122616 | 576 |
30 | 4611 | 138330 | 900 |
36 | 4400 | 158400 | 1296 |
30 | 4400 | 132000 | 900 |
28 | 4400 | 123200 | 784 |
30 | 4320 | 129600 | 900 |
30 | 4310 | 129300 | 900 |
21 | 4309 | 90489 | 441 |
44 | 4300 | 189200 | 1936 |
57 | 4300 | 245100 | 3249 |
30 | 4209 | 126270 | 900 |
44 | 4200 | 184800 | 1936 |
44 | 4200 | 184800 | 1936 |
11 | 4160 | 45760 | 121 |
11 | 4120 | 45320 | 121 |
8 | 4110 | 32880 | 64 |
49 | 4100 | 200900 | 2401 |
37 | 4100 | 151700 | 1369 |
7 | 4100 | 28700 | 49 |
8 | 4100 | 32800 | 64 |
37 | 4009 | 148333 | 1369 |
30 | 4009 | 120270 | 900 |
14 | 3920 | 54880 | 196 |
26 | 3900 | 101400 | 676 |
57 | 3866 | 220362 | 3249 |
36 | 3810 | 137160 | 1296 |
18 | 3809 | 68562 | 324 |
24 | 3809 | 91416 | 576 |
29 | 3802 | 110258 | 841 |
44 | 3800 | 167200 | 1936 |
34 | 3800 | 129200 | 1156 |
36 | 3800 | 136800 | 1296 |
36 | 3800 | 136800 | 1296 |
37 | 3800 | 140600 | 1369 |
37 | 3800 | 140600 | 1369 |
7 | 3800 | 26600 | 49 |
27 | 3800 | 102600 | 729 |
29 | 3800 | 110200 | 841 |
31 | 3800 | 117800 | 961 |
31 | 3800 | 117800 | 961 |
30 | 3730 | 111900 | 900 |
23 | 3709 | 85307 | 529 |
23 | 3702 | 85146 | 529 |
34 | 3700 | 125800 | 1156 |
36 | 3700 | 133200 | 1296 |
45 | 3700 | 166500 | 2025 |
37 | 3700 | 136900 | 1369 |
44 | 3700 | 162800 | 1936 |
30 | 3700 | 111000 | 900 |
Step 2: Find the sum of every column:
$$ \sum{X} = 5974 ~,~ \sum{Y} = 617090 ~,~ \sum{X \cdot Y} = 21015151 ~,~ \sum{X^2} = 245412 $$Step 3: Use the following equations to find $a$ and $b$:
$$ \begin{aligned} a &= \frac{\sum{Y} \cdot \sum{X^2} - \sum{X} \cdot \sum{XY} }{n \cdot \sum{X^2} - \left(\sum{X}\right)^2} = \frac{ 617090 \cdot 245412 - 5974 \cdot 21015151}{ 174 \cdot 245412 - 5974^2} \approx 3693 \\ \\b &= \frac{ n \cdot \sum{XY} - \sum{X} \cdot \sum{Y}}{n \cdot \sum{X^2} - \left(\sum{X}\right)^2} = \frac{ 174 \cdot 21015151 - 5974 \cdot 617090 }{ 174 \cdot 245412 - \left( 5974 \right)^2} \approx -4.258\end{aligned}$$Step 4: Substitute $a$ and $b$ in regression equation formula
$$ \begin{aligned} y~&=~a ~+~ b \cdot x \\y~&=~3693 ~-~ 4.258 \cdot x\end{aligned}$$Consider the following set of points: ${(-3 , -4), \, (2 , 3), \, (7 , 11)}$
a) Find the regression line for the given data points.
b) Plot the given points and the regression line.
The values of $X$ and their corresponding values of $Y$ are shown in the table below:
$$ \begin{array}{c|ccccc} X & ~1~ & ~2~ & ~3~ & ~4~ & ~5 \\ Y & ~4~ & ~8~ & ~9~ & ~11~& ~16 \end{array} $$Find a Pearson correlation coefficient.
Please tell me how can I make this better.