Consider the dissolved oxygen data in Exercise 8-81. Water quality engineers are interested in knowing whether these data support a claim that mean dissolved oxygen concentration is 2.5 milligrams per liter.
(a) Formulate an appropriate hypothesis testing procedure to investigate this claim.
(b) Test these hypotheses, using a = 0.05, and the data from Exercise 8-81.
(c) Find the P-value for this test.
(d) In Exercise 8-81(b) you found a 95% CI on the mean dissolved oxygen concentration. Does this interval provide useful additional information beyond that of the hypothesis testing results? Explain your answer.