The following scores represent a nurse’s assessment (X) and a physician’s assessment (Y) of the condition of 10 patients at time of admission to a trauma center.

X: 18 13 18 15 10 12 8 4 7 3 Y: 23 20 18 16 14 11 10 7 6 4

(a) Construct a scatter diagram for these data.

(b) Plot the following regression equations on the scatter diagram and indicate which one you think best fits the data. State the reason for your choice.

(1) ^y ¼ 8 þ 0:5x

(2) ^y ¼ 10 þ 2x

(3) y ¼ 1 þ 1x For each of the following exercises

(a) draw a scatter diagram and

(b) obtain the regression equation and plot it on the scatter diagram.