The equation of least squares regression line is .
The system of equations are
\ (Equation 1)
(Equation 2)
Observe the graph, the 6 points
are lie on the line graph, so n = 6.
(Expand of
)
(Substitute values of x - coordinates)
(Expand of
)
(Substitute values of y - coordinates)
(Expand of
)
(Substitute values of square of x - coordinates)
(Expand of
)
(Substitute values of xi yi)
(Write equation 1)
(Substitute
)
(Write equation 2)
(Substitute
)
Elimination Method: Change the system of equations are
\ (Write equation 3)
(Write equation 4)
Neither variable has a common coefficient.The coefficient of the b - variables are 6 and 15 and their least common multiply is 30, so multiply each equation by the values 5 and 2 that will make the b - coefficient 30.
Subtract the equations to eliminate b - variable.
\Write the equations in column form and add the corresponding columns.
\The result value is .
Now, find the b value by substitute in either equations.
(Write equation 3)
(Substitute
)
(Add 8.74 from each side)
(Divide each side by 6)
So, the equation of least squares regression line is .
The equation of least squares regression line is .