A researcher is investigating the effectiveness of a new
medication for lowering blood pressure for individuals
with systolic pressure greater than 140. For this
population, systolic scores average 160 with a
standard deviation of 20, and the scores form a
normal-shaped distribution. The researcher plans to
select a sample of n 25 individuals, and measure
their systolic blood pressure after they take the
medication for 60 days. If the researcher uses a
two-tailed test with .05,
a. What is the power of the test if the medication has
a 5-point effect?
b. What is the power of the test if the medication has
a 10-point effect?