Reconsider the previous two exercises.
a. Determine a 95% confidence interval for the difference in long-run probabilities of successfully abstaining from smoking between the two groups.
b. Interpret what this interval reveals. Be sure to address the question of whether the data provide strong evidence that the nicotine lozenge is more effective than the placebo.

Data from previous two exercises

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 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.