Question: Confidence Interval for Cigarette Tar – The mean tar content of a simple random sample of 25 unfiltered king size cigarettes is 21.1mg, with a standard deviation of 3.2mg. The mean tar content of a simple random sample of 25 filtered 100 mm cigarettes is 13.2mg with a standard deviation of 3.7 mg. Construct a 90% confidence interval estimate of the difference between the mean tar content of unfiltered king size cigarettes and the mean tar content of filtered 100 mm cigarettes. Does the result suggest that 100 mm filtered cigarettes have less tar than unfiltered king size cigarettes?