A process for a certain type of ore is designed to reduce the concentration of impurities to less than 2%. It is known that the standard deviation of impurities for processed ore is 0.6%. Let µ represent the mean impurity level, in percent, for ore specimens treated by this process. The impurity of 80 ore specimens is measured, and a test of the hypothesis H0: µ > 2 versus H1: µ < 2 will be performed.
a. If the test is made at the 1% level, what is the rejection region?