A psychologist studying addiction tests whether cravings for cocaine and relapse

Question

A psychologist studying addiction tests whether cravings for cocaine and relapse are independent. The following table lists the observed frequencies in the small sample of people who use drugs. Obs. Freq. Relapse Yes No Cravings Yes 21 13 34 No 6 19 25 27 32 N = 59 (a) Conduct a chi-square test for independence at a 0.05 level of significance. (Round your answer to two decimal places.) = Decide whether to retain or reject the null hypothesis. Retain the null hypothesis. Reject the null hypothesis. (b) Compute effect size using and Cramer's V. Hint: Both should give the same estimate of effect size. (If necessary, round your intermediate steps to two or more decimal places. Round your answers to two decimal places.) = V =

Explanation / Answer

soL:

HO:CRAVINGS AND RELAPSE ARE INDEPENDENT

H1:CRAVINGS AND RELAPSE ARE DEPENDENT

ALPHA=0.05

chi sq stat= TOTALO-E)^2/E

E-expected frequcnies

O-observed freq

E=rowtotal8colum tot/grandtotal

Expected ffeq are

=34*27/59

=34*32/59

=25*27/59

=25*32/59

Chi sq stat=8.28

df=rows-1*columsn-1

=(2-1)(2-1)

=1

alpha=0.05

p=0.004

p=0.00

p<0.05

Reject Null hypothesis

Accept alternative hypothesis

there is sufficient evidence at 5% level of signiifcance to conclude that

CRAVINGS AND RELAPSE ARE DEPENDENT.

Solutionb:

PHI=SQRT(CHISQ/n)

=sqrt(8.28/59)

=0.37

Cramer's V=sqrt(chi sq/n*df)

=sqrt(8.28//591)

=0.37

cramers v=0.37

RELAPSE CRAVINGS YES NO TOTAL YES 21 13 34 NO 6 19 25 TOTAL 27 32 59 =-->GRAND TOTAL

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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