To determine whether the Wilson Company is complying with federal requirements for cleaning its wastewater, sample measurements are taken every so often. One requirement is that the average pH level not exceed 7.4. Suppose a sample of 95 pH measurements has been taken. The data for these measurements are shown in a file called Wilson Water.

a. Considering the requirement for pH level, state the appropriate null and alternative hypotheses. Discuss why it is appropriate to form the hypotheses with the federal standard as the alternative hypothesis.

b. Based on the sample data of pH levels, what should the company conclude about its current status on meeting the federal requirement? Test the hypothesis at the 0.05 level. Discuss your results in a memo to the company’s environmental relations manager.