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:
$$\begin{array}{c|ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc}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end{array}$$The equation of the regression line is:
$$y~=~3815 ~-~ 6.559 \cdot x$$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.
$X$ | $Y$ | $X\cdot Y$ | $X \cdot X$ |
62 | 3300 | 204600 | 3844 |
51 | 3243 | 165393 | 2601 |
44 | 3800 | 167200 | 1936 |
44 | 3510 | 154440 | 1936 |
44 | 3600 | 158400 | 1936 |
57 | 3401 | 193857 | 3249 |
44 | 3312 | 145728 | 1936 |
57 | 3000 | 171000 | 3249 |
62 | 3210 | 199020 | 3844 |
43 | 3400 | 146200 | 1849 |
50 | 3202 | 160100 | 2500 |
57 | 3376 | 192432 | 3249 |
44 | 3500 | 154000 | 1936 |
45 | 3360 | 151200 | 2025 |
49 | 4100 | 200900 | 2401 |
60 | 3500 | 210000 | 3600 |
44 | 3000 | 132000 | 1936 |
44 | 3010 | 132440 | 1936 |
62 | 3100 | 192200 | 3844 |
44 | 4200 | 184800 | 1936 |
44 | 4200 | 184800 | 1936 |
44 | 3600 | 158400 | 1936 |
51 | 3300 | 168300 | 2601 |
34 | 3700 | 125800 | 1156 |
44 | 3600 | 158400 | 1936 |
34 | 3800 | 129200 | 1156 |
44 | 3411 | 150084 | 1936 |
62 | 3300 | 204600 | 3844 |
36 | 4400 | 158400 | 1296 |
44 | 3500 | 154000 | 1936 |
36 | 3800 | 136800 | 1296 |
36 | 3700 | 133200 | 1296 |
44 | 3600 | 158400 | 1936 |
44 | 3200 | 140800 | 1936 |
37 | 4100 | 151700 | 1369 |
44 | 3110 | 136840 | 1936 |
49 | 3500 | 171500 | 2401 |
44 | 3350 | 147400 | 1936 |
44 | 3400 | 149600 | 1936 |
39 | 3350 | 130650 | 1521 |
39 | 3200 | 124800 | 1521 |
39 | 3388 | 132132 | 1521 |
49 | 3500 | 171500 | 2401 |
49 | 3310 | 162190 | 2401 |
49 | 3500 | 171500 | 2401 |
41 | 3500 | 143500 | 1681 |
41 | 3500 | 143500 | 1681 |
43 | 3500 | 150500 | 1849 |
49 | 3500 | 171500 | 2401 |
49 | 3300 | 161700 | 2401 |
Step 2: Find the sum of every column:
$$ \sum{X} = 5996 ~,~ \sum{Y} = 628280 ~,~ \sum{X \cdot Y} = 21261331 ~,~ \sum{X^2} = 245896 $$Step 3: Use the following equations to find $a$ and $b$:
$$ \begin{aligned} a &= \frac{\sum{Y} \cdot \sum{X^2} - \sum{X} \cdot \sum{XY} }{n \cdot \sum{X^2} - \left(\sum{X}\right)^2} = \frac{ 628280 \cdot 245896 - 5996 \cdot 21261331}{ 175 \cdot 245896 - 5996^2} \approx 3815 \\ \\b &= \frac{ n \cdot \sum{XY} - \sum{X} \cdot \sum{Y}}{n \cdot \sum{X^2} - \left(\sum{X}\right)^2} = \frac{ 175 \cdot 21261331 - 5996 \cdot 628280 }{ 175 \cdot 245896 - \left( 5996 \right)^2} \approx -6.559\end{aligned}$$Step 4: Substitute $a$ and $b$ in regression equation formula
$$ \begin{aligned} y~&=~a ~+~ b \cdot x \\y~&=~3815 ~-~ 6.559 \cdot x\end{aligned}$$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.