4. (30pts) Does the rate of serious mental illness among substance abusers vary according to the

type of substance abused? To find out, a psychiatrist collected data on the mental health

of a random sample of substance abusers: drug abusers, alcohol abusers, and abusers of

both drugs and alcohol. His results were as follows:

Substance Abused

Mental illness? Drugs Alcohol Drugs & Alcohol

Yes 12 8 16

No 31 33 35

a) (2pts)Which is the independent variable and which is the dependent variable?

b) (3pts)What is null and research hypothesis?

c) (3pts)Which test should you use?(Two sample independent t, ANOVA , Chi-square, or correlation)?

d) (8pts) Compute the appropriate test statistic (Note: please show all your work as much as you can)

e) (5pts) Please make a decision whether the null hypothesis is rejected when = .05 and one tailed test. Please include critical statistics from the correct distribution chart (e.g., Z distribution, T distribution, F distribution, or Chi-square distribution)

f) (4pts) Provide an interpretation with overall sentence about the conclusion reached

g) (5pts) Find the pattern of the relationship. You should include proportions/percentage to justify your answer.

5. (9pts) Please indicate whether the following statements show positive or negative relationships:

Positive Negative

more children you have, the less amount of sleep you get. O O

higher your driving speed, the more likely you are to be pulled over. O O

less you study, the less likely you are to graduate. O O

6. (4pts) Below are four r (correlation) values. Please put them in order from the weakest to the strongest:

.59 -.21 .07 -.86