A researcher wishes to determine whether people with high blood pressure can reduce their blood pressure by following a particular diet.
(a) Use the sample data below to test the claim that the treatment population’s mean μ1 is smaller than the control population’s mean μ2. Test the claim using a significance level of 0.01. Test the indicated claim about the means of two populations. Assume that the two samples are independent and that they have been randomly selected. Identify the null hypothesis, alternative hypothesis, test statistic, P-value, conclusion about the null hypothesis, and final conclusion that addresses the original claim.
n1 = 85, n2 = 75, x1-bar = 189.1, x2-bar = 203.7, s1 = 38.7, s2 = 39.2
(b) Use the sample data above to construct a 99% confidence interval for u1 – u2 where u1 and u2 represent the mean for the treatment group and the control group respectively. Interpret the confidence interval in the context of the study described in problem 3 above.