Question

A psychologist studying addiction tests whether craving for cocaine and relatere independent. The following the trends in the come No Cravings 20 10 No 19 2029 N (a) Conduct a chi-square test for independence at 0.05 level of sound you to the decimal place.) Decide whether to retain or reject the nut hypothesis O Retain the ruil hypothes O Reject the null hypothesis Computer effects using and Cramer's V. Mithoth whetheme fecer, round your internet tapetowar mere end den - You may need to use the appropriate table in Appendix tower this question

Answer 1

Applying chi square test of independence:

Expected	Ei=row total*column total/grand total	Yes	No	Total
	yes	15.0000	15.0000	30
	No	14.0000	14.0000	28
	total	29	29	58
chi square    χ2	=(Oi-Ei)2/Ei	Yes	No	Total
	yes	1.667	1.667	3.3333
	No	1.786	1.786	3.5714
	total	3.4524	3.4524	6.9048
test statistic Xobt2=		6.90
p value =	0.0086	from excel: chidist(6.9048,1)

reject the null hypothesis

b)

Phi cpefficieint =φ=√(X2/n)=

0.35

Cramer V=√(X2/(n*(k-1)))=

0.35