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 YesNo CravingsYes211031 No71724 2827N = 55 (a) Conduct a chi-square test for independence at a 0.05 level of significance. (Round your answer to two decimal places.) $ \chi_{obt}^2 $ = Decide whether to retain or reject the null hypothesis. Retain the null hypothesis. Reject the null hypothesis. (b) Compute effect size using ϕ 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.) ϕ= V=