(20 points) Problem #7 Cocaine addiction is very hard to break. Even among addicts trying hard to break the addiction, relapse is common. Addicts need cocaine to feel any pleasure, so perhaps giving them an antidepressant drug will help. A three year experiment investigated the effectiveness of two drugs, desipramine and lithium, in the treatment of cocaine addiction The subjects in the study were a rand re a random sample of cocaine addicts seeking treatment. The 72 subjects were randomly assigned to one of the three treatme e treatment groups (desipramine, lithium or placebo with 24 subjects in each group) and the study was double-blind. The results are summarized in the following table. Outcome Relapse No relapse Treatment Desipramine 14 Lithium 18 Placebo (a) What are the two categorical variables? How many categories are there for each variable? Categorical Variable #1 outcome Number of Categories 2 ( relapse or no ) Categorical Variable #2 treat ment desipramine) mber of Categories 3 lithium (b) What percentage of the subjects in the sample relapsed? There is a level. chance that the subjects in the sample will relapse (c) What percentage of the subjects in the sample taking desipramine relapsed? There is a 41. 471%. chance that the subjects in the sample will relapse. taking desipramine (d) What percentage of the subjects in the sample taking the placebo relapsed? There is a 83.331. chance that the subjects taking placebo will relapse. There (e) What percentage of the subjects in the sample taking litium relapsed? IS taking litium a 751. chance that subjects Problem is continued on next page ... will relapse. Problem continued from previous page... (f) A researcher is interested in determining if there is evidence that treatment and outcome are not independent. Have the necessary conditions been satisfied so that a chi-square test of independence can be performed? yes, the necessary conditions have been satisfied, so that a chi-square test of independence 3. At most 201. of cells can be performed. have less than 1. It Is a random sample observations 2. There is at least ane observation in each Cell. (g) Perform the appropriate test to determine if outcome (relapse, no relapse) is independent of method of treatment. Use a = 0.05. Clearly show the 6 steps of hypothesis testing. Step 1 : Ho