1. Determine whether the samples are independent or dependent.

The effectiveness of a new headache medicine is tested by measuring the amount of time before the headache is cured for patients who use the medicine and another group of patients who use a placebo drug. Explain.

2. Determine whether the samples are independent or dependent.

The effectiveness of a headache medicine is tested by measuring the intensity of a headache in patients before and after drug treatment. The data consist of before and after intensities for each patient. Explain.

3. In a random sample of 500 people aged 20-24, 22% were smokers. In a random sample of 450 people aged 25-29, 14% were smokers. Test the claim that the proportion of smokers in the two age groups is the same. Use a significance level of 0.01. Show all steps of the hypothesis test and all calculations.

4. A researcher wishes to determine whether people with high blood pressure can reduce their blood pressure by following a particular diet. Use the sample data below to construct a 99% confidence interval for µ1 - µ2 where µ 1 and µ2 represent the mean for the treatment group and the control group respectively. Show all steps of the hypothesis test and all calculations. Use the following t-distribution table www.itl.nist.gov/div898/handbook/eda/section3/eda3672.htm

Treatment Group...................................Control Group

n1 = 85.......................................................n2 = 75

x bar 1= 189.1......................................x bar 2 = 203.7

s1 = 38.7...................................................s2 = 39.2