Telephone survey completion rates. The study described in Exercise 17.14 also kept tabs of whether leaving advanced messages increased the likelihood of ultimately completing the interview. Data for this outcome are tallied in Table 17.8. Perform analyses similar to those requested in the prior exercise. To what extent did the advanced messages increase the response rate?

TABLE 17.8 Data for Exercise 17.15. Response to telephone survey according to whether an advanced message was left.