Question

5. One year, investigators studied the relationship between alcohol consumption by cllege students and GPA. They surveyed a simple sample of 4278 US college students and generated the following stats:

x?=6	SDx=4
?=2.9	SDy=1.2	r= -0.6

where the x j = number of alcoholic drinks consumed per week by the jth student, and y j = the year-end GPA of the jth student.

a.) What does the fact that the correlation is negative say about the relation between drinking alcohol andgrades in school?

b.) Assuming that the scatter diagram for the alcohol-GPA data is football shaped, find the approximated percentage of all US college students who consumes 8 alcoholic drinks per week that have a GPA of 3.7 or more.

Answer 1

a.) What does the fact that the correlation is negative say about the relation between drinking alcohol andgrades in school?

Ans: The fact that the correlation is negative say about the relationship between drinking alcohol and grades in school is that for increase the drinking alcohol decreases the grades in school.

b.) Assuming that the scatter diagram for the alcohol-GPA data is football-shaped, find the approximated percentage of all US college students who consume 8 alcoholic drinks per week that have a GPA of 3.7 or more.