A researcher plans to conduct an experiment evaluating the effect of a treatment. A sample of n=9 participants is selected a each person receives the treatment before being tested on a standardized dexterity task. The treatment is expected to lower scores on the test by average of 330 points. For the regular population, scores on the dexterity task form a normal distribution with u=240 and 0=30.
a. If the researcher uses a two-tailed test with ox=.05, what is the power of the hypothesis test?
b. again assuming a two-tailed test with ox=.05, what is the power of the hypothesis test if the sample size is increased to n=25?