CORRELATION AND REGRESSION

1. The following data represents the number of days absent, x, and the final grade, y, for a sample of college students in a general education course at a large university.

absences	x	0	1	2	3	4	5
Final grade	y	86	84	81	78	74	64

1. Find the correlation coefficient. __________________________________

1. Find the regression equation.____________________________________

1. Predict the final grade of a student who had 6 absences.______________

2. A researcher conducts a study to determine whether there is a linear relationship between a person's height (in inches) and pulse rate (in beats per minute). The data are shown in the table below

Heights,	68	72	65	71	63	74	78	64	68
Pulse rate,	91	95	87	94	84	97	100	85	92

1. Find the correlation coefficient r.
2. Find the regression equation.
3. Graph the regression equation.

(3) Given the x and y data pairs below:

x	20	10	30	40	60	70
y	20	20	30	50	60	80

a. Make a scatter diagram.

b. Give the correlation coefficient.

c. Give the regression equation.

d. Draw the regression line on the scatter diagram using the yp points.

e. Find y for x = 50

(4) Given the x and y data pairs below:

x	10	10	30	30	40	50
y	20	30	30	40	50	60

a. Make a scatter diagram on graph paper.

b. Give the correlation coefficient.

c. Give the regression equation.

d. Draw the regression line on the scatter diagram using the yp points.

e. Find y for x = 20