Reconsider the previous exercise. At the end of the 52-week study, 17.9% of those in the nicotine group had successfully abstained from smoking, compared to 9.6% of those in the placebo group.
a. Produce a 2 × 2 table of counts to represent these data.
b. Create a relevant graph to display the data.
c. Calculate and interpret the difference in the conditional proportions who had successfully abstained from smoking.
d. Calculate and interpret the ratio of the conditional proportions who had successfully abstained from smoking.

e. Conduct an appropriate theory-based test to investigate whether the percentages who successfully abstained from smoking differ significantly between the two groups. Report the test statistic and p-value and summarize your conclusion.
f. Do you think the researchers would be pleased with the result of this significance test? Explain why or why not.
g. Do you think a cause-and-effect conclusion (between using the nicotine lozenge and being more likely to abstain from smoking) is justified based on this study? Explain.

Data from previous exercise

A study conducted in 2002 by Shiff man, Dressler, Hajeh, and Gilburt investigated whether a nicotine lozenge is helpful for smokers trying to quit smoking. The researchers recruited smokers who were interested in quitting through advertisements near four sites in the United Kingdom and 11 sites in the United States. Those smokers who met the screening qualifications were randomly assigned to one of two groups: One group received nicotine lozenges and the other group received placebo lozenges. The subjects were compared on various background variables at the beginning of the study, and at the end of the study they were compared on whether or not they successfully abstained from smoking. Of the 459 subjects in the nicotine group, 42.9% were male. Of the 458 subjects in the placebo group, 40.2% were male.