Question

A therapist measures the relationship between a patient's expectations that therapy will be successful and the actual success of the therapy. The following table shows the results of this hypothetical study using a sample of 50 clients.

  

	yes	no	total
yes	24	8	32
no	4	14	18
total	28	22

(a) Compute the phi correlation coefficient. (Round your answer to three decimal places.) 0

(b) Using a two-tailed test at a 0.05 level of significance, state the decision to retain or reject the null hypothesis. Hint: You must first convert r to χ2. R

Answer 1

a)

from above phi coefficient =0.510

b)

X² =(phi coefficient)²*n =13.023

for 1 df and 0.05 level , critical value       χ2=

3.841

since test statistic is in rejection region;

reject the null hypothesis