
Answer:
The y-intercept of the least squares line is 7 and slope of the line is 1.1. It means x and y are positively related.
Step-by-step explanation:
Least squares : It is an approach to find a regression line such that the sum of squares of residual(difference between estimated point on the line and data point) is minimum.
The given points are (10,10), (20,50),​ (40,20), and​ (50,80).
The least squares line is
[tex]y=7.0+1.1x[/tex] Â Â Â Â Â Â .... (1)
The general form of least squares line is
[tex]y=a+bx[/tex] Â Â Â Â Â Â .... (2)
where, a is y-intercept and b is slope of the line.
On comparing (1) and (2) we get
[tex]a=7.0,b=1.1[/tex]
It means the y-intercept of the least squares line is 7 and slope of the line is 1.1.
Slope is positive it means x and y are positively related.