Chantrix is a medication prescribed for smoking cessation that works by targeting nicotine receptors in the brain.

1927 smokers who desired to quit smoking volunteered to take part in a study of Chantrix.

At the end of 12 weeks, 1236 of them had been able to quit smoking.

These questions are about a 99% confidence interval for the population proportion of smokers desiring to quit who would succeed by the end of 12 weeks of using Chantrix.

1.1 What proportion of the participants successfully quit smoking by the end of 12 weeks of using Chantrix?

1.2 Explain why the conditions to use the normal approximation to find a confidence interval are satisfied.

1.3 State the formula and calculate the standard error for the confidence interval

1.4 What is the z* value needed to calculate a 99% confidence interval?

1.5 What are the lower and upper limits of the 99% confidence interval?

1.6 Based on your confidence interval, do these data support a claim that at least 70% of individuals who desire to quit smoking will succeed in 12 weeks of Chantrix use?

1.7Explain why a study with a control group receiving a placebo is necessary to assess the effectiveness of Chantrix.