7.111 Changing the significance level. In Example 7.24 (page 468), we assessed the power of a new study of calcium on blood pressure assuming n1 = n2 = 45 subjects. The power was based on α = 0.01. Suppose that we wanted to use α = 0.05 instead.
(a) Would the power increase or decrease? Explain your answer in terms someone unfamiliar with power calculations can understand.
(b) Verify your answer by computing the power.