Chapter 9, Problem 9.59SE

i.

To determine

Null hypothesis and alternative hypothesis.

ii.

To determine

To identify: alternative hypothesis in part (i) imply a one or two tailed test.

iii.

To determine

To identify: The difference $\overline{x}-7.5=-0.2$ is large enough to indicate mean $pH$ of water samples is less than $7.5$ by just glancing at the data.

iv.

To determine

Test statistics of the hypothesis in part (i).