Assignment:
Assume that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal, unless your instructor stipulates otherwise.
Confidence Interval for Cigarette Nicotine Refer to the sample data in Exercise 19 and construct a 95% confidence interval estimate of the difference between the mean nicotine amount in menthol cigarettes and the mean nicotine amount in nonmenthol cigarettes. What does the result suggest about the effect of menthol?
Exercise 19
Hypothesis Test for Cigarette Nicotine Scientists collect a simple random sample of 25 menthol cigarettes and 25 nonmenthol cigarettes. Both samples consist of cigarettes that are filtered, 100 mm long, and non-light. The menthol cigarettes have a mean nicotine amount of 0.87 mg and a standard deviation of 0.24 mg. The nonmenthol cigarettes have a mean nicotine amount of 0.92 mg and a standard deviation of 0.25 mg. Use a 0.05 significance level to test the claim that menthol cigarettes and nonmenthol cigarettes have different amounts of nicotine. Does menthol appear to have an effect on the nicotine content?