Answer:
[tex]m=-\frac{13}{20.8}=-0.625[/tex]
Nowe we can find the means for x and y like this:
[tex]\bar x= \frac{\sum x_i}{n}=\frac{16}{5}=3.2[/tex]
[tex]\bar y= \frac{\sum y_i}{n}=\frac{35}{5}=7[/tex]
And we can find the intercept using this:
[tex]b=\bar y -m \bar x=7-(-0.625*3.2)=9[/tex]
So the line would be given by:
[tex]y=-0.625 x +9[/tex]
Step-by-step explanation:
We have the following data:
X: 3,3,2,1,7
Y:6,7,8,9,5
We want to find an equationinf the following form:
[tex] y= bX +a[/tex]
[tex]a=m=\frac{S_{xy}}{S_{xx}}[/tex]
Where:
[tex]S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}[/tex]
[tex]S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}[/tex]
So we can find the sums like this:
[tex]\sum_{i=1}^n x_i = 3+3+2+1+7=16[/tex]
[tex]\sum_{i=1}^n y_i =6+7+8+9+5=35[/tex]
[tex]\sum_{i=1}^n x^2_i =72[/tex]
[tex]\sum_{i=1}^n y^2_i =255[/tex]
[tex]\sum_{i=1}^n x_i y_i =99[/tex]
With these we can find the sums:
[tex]S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=72-\frac{16^2}{5}=20.8[/tex]
[tex]S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}=99-\frac{16*35}{5}=-13[/tex]
And the slope would be:
[tex]m=-\frac{13}{20.8}=-0.625[/tex]
Nowe we can find the means for x and y like this:
[tex]\bar x= \frac{\sum x_i}{n}=\frac{16}{5}=3.2[/tex]
[tex]\bar y= \frac{\sum y_i}{n}=\frac{35}{5}=7[/tex]
And we can find the intercept using this:
[tex]b=\bar y -m \bar x=7-(-0.625*3.2)=9[/tex]
So the line would be given by:
[tex]y=-0.625 x +9[/tex]
