Chapter 9.3, Problem 67E

a.

To determine

Test the hypothesis $H_0:\mu =4\text{ vs }{H}_0:\mu \ne 4$ at the level of significance $\alpha =0.01$ and to find the P-value.

b.

To determine

Check the normality assumption.

c.

To determine

Compute the power of the test if the true mean dissolved oxygen concentration is as low as 3.

d.

To determine

Find the sample size required to detect a true mean dissolved oxygen concentration as low as 2.5 if the power of the test is wanted to be at least 0.9.

e.

To determine

Explain how you could answer the question in part (a) with a two sided confidence interval.