stats hw help! thanks! Cocaine produces short-term feelings of physical and ment

Question

stats hw help! thanks!

Cocaine produces short-term feelings of physical and mental well-being, followed by feelings of tiredness and depression once the drug wears off This cycle of positive and negative feelings is the root problem of addiction and can be very hard to break. Perhaps giving cocaine addicts a medication that fights depression can help them break the addiction. A three-year study compared an antidepressant called desipramine with lithium (a standard treatment for cocaine addiction) and a placebo. The subjects were 72 chronic users of cocaine who wanted to break their drug habit. Twenty-four of the subjects were randomly assigned to each treatment. Here are the counts and proportions of the subjects who avoided relapse into cocaine use during the study: Group Treatment Subjects No relapse Proportion 0.583 0.250 0.167 14 1 Desipramine 24 24 24 Lithium 3 Placebo Does data analysis suggest that desipramine is more successful than the other two treatments? Are there significant differences among the outcomes for the treatments? eBook Step 1: FORMULATE: The chi-square tests the null hypothesis There is no relationship between treatment type and outcome SOLVE: True or False: The successful rate of non relapse is highest with desipramine and lowest with the placebo. O True O False

Explanation / Answer

> tab=matrix(c(14,10,6,18,4,20),byrow=T,nrow=3)
> tab
[,1] [,2]
[1,] 14 10
[2,] 6 18
[3,] 4 20
> rownames(tab)=c("Desipramine","Lithium","Placebo")
> colnames(tab)=c("No.relapse","Relapse")
> tab=as.table(tab)
> tab
No.relapse Relapse
Desipramine 14 10
Lithium 6 18
Placebo 4 20
> chisq.test(tab)

Pearson's Chi-squared test

data: tab
X-squared = 10.5, df = 2, p-value = 0.005248

Step 1 : TRUE since p-value < 0.05 implies rejection of null hypothesis.

Step 2 : YES

Step 3 : P-value < 0.01

Step 4 : There is strong evidence that different treatments lead to significatnly different relapse rates. Desipramine has the highest rate of subjects who do not relapse into cocaine addiction. ( since p-value is small and we reject H0)

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.