one of the points in a set of points if (4,8). What is the residual for this point if the equation of the regression line for these points is y=3.6+1.8x
To find the residual for a given point in a regression line, you need to subtract the predicted value from the observed value.
In this case, the equation of the regression line is y = 3.6 + 1.8x, and the point in question is (4, 8).
Step 1: Plug in the x-value, which is 4, into the regression equation to find the predicted y-value:
y = 3.6 + 1.8(4)
y = 3.6 + 7.2
y = 10.8
Step 2: Subtract the observed y-value, which is 8, from the predicted y-value, which is 10.8:
Residual = 8 - 10.8
Residual = -2.8
Therefore, the residual for the point (4, 8) is -2.8.