The mean diastolic blood pressure among American men aged 18-44 is known to be 81 mmHg. A random sample 150 Canadian males in the same age group yielded a mean diastolic blood pressure of 78.75 mm Hg with a standard deviation of 12 mm Hg.
(a) Is there sufficient evidence at ? = .01 to conclude that the mean diastolic blood pressure among Canadian men aged 18-44 differs significantly from that of their American counterparts? (Use the t-test; the procedure is outlined on pg 58 of the text).
(b) What assumption (if any) about the population (from which the sample came) should hold in order that the t-test in (a) be valid? Explain.
(c) Conduct the test in (a) using a confidence interval with the appropriate level of confidence.