A recent study showed that the amount of sleep college students get each night could be described by model that is roughly bell shaped with x =6.5 hours and s = .42 hours. Use the Empirical Rule to describe the distribution. (There should be three parts to your answer and the answer should be stated in terms of the problem. For example: XX% of college students sleep between ____ and ____ )

a) There are two criteria that a data set must satisfy in order for us to perform a linear regression analysis. State these two criteria.

b) Find and state the linear regression line to predict walking hours from age. (Be sure your answer is the equation of a line and express all numbers to three decimal places.)

c) State (to three decimal places) and interpret the y-intercept of this model. The interpretation must be in terms of the example. (Sometimes the interpretation of a y-intercept is not very meaningful for a given situation. That is OK. I still want you to interpret it.)

d) State (to three decimal places) and interpret the slope of this model. The interpretation must be in terms of the example

e) Predict the number of hours walked for a person who is 58 years of age.

f) Find the residual for the person in the study who is 28 years old.

Age (years)	Time spent walking each week (hrs)
65	0.8
47	3.9
52	3.9
44	5.1
42	4.2
67	1.0
53	3.0
25	7.1
38	4.2
58	3.2
32	6.7
61	3.2
25	5.3
26	5.3
27	6.7
34	5.9
42	5.7
45	2.2
42	3.1
28	6.9