1. Explain how the power of a hypothesis test is influenced by each of the following. Assume that all other factors are held constant.
a. Increasing the alpha level from .01 to .05.
b. Changing from a one-tailed test to a two-tailed test.
2. A researcher is evaluating the influence of a treatment using a sample selected from a normally distributed population with a mean of 80 and a standard deviation of 20. The researcher expects a 12-point treatment effect and plans to use a two-tailed hypothesis test with alpha = .05.
a. Compute the power of the test if the researcher uses a sample of n = 16 individuals.
b. Compute the power of the test if the researcher uses a sample of n = 25 individuals.