Amedical experiment is planned to compare the herb echinacea with a placebo for preventing colds. one response variable will be "volume of nasal secretions" (if you have a cold, you blow your nose a lot). suppose the average volume of nasal secretions in people without colds is 2. an increase to 6 indicates a cold.

(a) which of the following describes the meaning of the significance level ? for a test of the hypotheses: h0: mu = 2 versus ha: mu > 2 ?

a) alpha is the probability of selecting a sample whose data leads us to the decision to reject h0 when in reality mu = 2 is true.

b) alpha is the probability of selecting a sample whose data leads us to the decision fail to reject h0 when in reality mu = 6 is true.

(b) the power of the test in (a) when the true value of the population mean is mu = 6 is

a) the probability of selecting a sample whose data leads us to the decision to reject h0when mu = 6 is true.

b) the probability of selecting a sample whose data leads us to the decision to fail to reject h0 when mu = 2 is true.