sedentary persons in this age group is planned to test whether they have
higher levels of plasma glucose than the general population.
(a) Set up the null and alternative hypotheses.
(b)If the real increase is 0.1 log unit, what is the power of such a study if
a two-sided test is to be used witha¼ 0 :05?5.15 Suppose that we are interested in investigating the e¤ect of race on level
of blood pressure. The mean and standard deviation of systolic blood
pressure among 25- to 34-year-old white males were reported as
128.6 mmHg and 11.1 mmHg, respectively, based on a very large sample.
Suppose that the actual mean for black males in the same age group is
135 mmHg. What is the power of the test (two-sided, a¼ 0 :05) if
n¼100 and we assume that the variances are the same for whites and
blacks?
EXERCISES 207