10. Cocaine addiction can be difficult to overcome. Since addicts derive pleasure from the drug, one proposed aid is to provide an antidepressant drug. A 3-year study with 72 chronic cocaine users compared an antidepressant drug called desipramine with lithium and a placebo. (Lithium is a standard drug to treat cocaine addiction. A placebo is a tablet with no effects that tastes and looks like the antidepressant drug. It is used so that the effect of being in the study but not taking the antidepressant drug can be seen.) One-third of the subjects, chosen at random, received each treatment. Here are the results:
Cocaine relapse?
Treatment Yes No
Desipramine 10 14
Lithium 18 6
Placebo 20 4
a. Compute P(Yes | Desiprimine) (3 pts)
b. Compute P(Yes | Lithium) (3 pts)
c. Compute P(Yes | Placebo) (3 pts)
d. Explain the difference between P(Yes | Desiprimine) and P( Desiprimine | Yes) (3 pts)
e. Use parts a, b, c to draw a bar graph. Write a brief summary of your conclusions. (3 pts)