That is calledĮxtrapolation, and it can produce unreasonable The range of values used to create the equation. Warning: When you use a regression equation,ĭo not use values for the independent variable that are outside Test, the estimated statistics grade (ŷ) would be: In our example, the independent variable is the student's score ChooseĪ value for the independent variable ( x), perform theĬomputation, and you have an estimated value (ŷ) Once you have the regression equation, using it is a snap. Therefore, the regression equation is: ŷ = 26.768 + 0.644x. Once we know the value of the regression coefficient (b 1), we can solve for the regression slope (b 0): Regression analysis come from the above three tables.įirst, we solve for the regression coefficient (b 1):ī 1 = Σ / Σ The regression equation is a linear equation of the form:Īnalysis, we need to solve for b 0 and b 1.Ĭomputations are shown below.
Student x i y i (x i- x) 2 (y i- y) 2 1 95 85 289 64 2 85 95 49 324 3 80 70 4 49 4 70 65 64 144 5 60 70 324 49 Sum 390 385 730 630 Mean 78 77Īnd finally, for each student, we need to compute the product of theĭeviation scores (the last column in the table below). Student x i y i (x i- x) (y i- y) 1 95 85 17 8 2 85 95 7 18 3 80 70 2 -7 4 70 65 -8 -12 5 60 70 -18 -7 Sum 390 385 Mean 78 77Īnd for each student, we also need to compute the squares of the deviation scores (the last two columns in the table below). Scores that we will use to conduct the regression analysis. Student's score and the average score on each measurement. The last two columns show deviations scores - the difference between the Similarly, the y i column shows statistics In the table below, the x i column shows scores on theĪptitude test.
#HOW TO WRITE A SIMPLE LINEAR REGRESSION EQUATION HOW TO#