Solve the following problems:
- The mean tar content of a simple random sample of 25 unfiltered king-size cigarette is 21.1 mg, with a standard deviation of 3.2 mg. The mean tar content of a simple random sample of 25 filtered 100 mm cigarettes is 13.2 mg with a standard deviation of 3.7 mg.
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.
- Use a 0.05 significance level to test the claim that unfiltered king-size cigarettes have mean tar content greater than that of filtered 100 mm cigarettes.
- What does the result suggest about the effectiveness of cigarette filters?
- Listed below are systolic blood pressure measurements (mm Hg) taken from the right and left arms of the same woman. Use a 0.05 significance level to test for a difference between the measurements from the two arms. What do you conclude? Assume that the paired
sample data are simple random samples and that the differences have a distribution that is approximately normal.
Right Arm - 102 101 94 79 79
Left Arm - 175 169 182 146 144