This exercise shows how to compute the slope and the

Chapter 4, Problem 45

(choose chapter or problem)

This exercise shows how to compute the slope and the yintercept of the regression line. As an example, well work with the simple data set given in Exercise 27. x 1234 y 0367 (a) Let x denote the sum of the x-coordinates in the data set, and let y denote the sum of the y-coordinates. Check that x 10 and y 16. (b) Let x2 denote the sum of the squares of the x-coordinates, and let xy denote the sum of the products of the corresponding x- and y-coordinates. Check that x2 30 and xy 52. (c) The slope m and the y-intercept b of the regression line satisfy the following pair of simultaneous equations [in the first equation, n denotes the number of points (x, y) in the data set]: In the present example these equations become e 4b 10m 16 10b 30m 52 e nb Solve this pair of equations for m and b, and check thatyour answers agree with the values in Exercise 27(c).