determine the equation of the regression line x 12 21 28 8 2

determine the equation of the regression line. x 12 21 28 8 20 y 17 15 22 19 24

Solution

We will find an equation of the regression line in 4 steps.

Step 1: Find XY and X² as it was done in the table below.

Step 2: Find the sum of every column:

X=89 , Y=97 , XY=1785 , X²=1833

Step 3: Use the following equations to find a andb:

a=YX²XXY/nX²(X)²=971833891785/5.183389²15.222

b=nXYXY/nX²(X)²=517858997/51833(89)²0.235

Step 4: Substitute a and b in regression equation formula

y y = a + bx= 15.222 + 0.235x