A pharmaceutical manufacturer is concerned that the impurity concentration in pills should not exceed 3%. It is known that from
a particular production run impurity concentrations follow a normal distribution with a standard deviation of 0.4%. A random sample of 64 pills from a production run was checked, and the sample mean impurity concentration was found to be 3.07%. Testing at the 5% level the null hypothesis that the population mean impurity concentration is 3% against the alternative that it is more than 3%. a. Calculate the p-value for this test.
b. Find the p-value for this test and draw your conclusion.
c. Suppose that the alternative hypothesis in part b had been two-sided rather than one-sided. Conduct your test using either the critical value or the p-value approach.
