10.18 Water specimens are taken from water used for cooling as it is being discharged from a power plant into a river. It has been determined that as long as the mean temperature of the discharged water is at most 1508F, there will be no negative effects on the river’s ecosystem. To investigate whether the plant is in compliance with regulations that prohibit a mean discharge water temperature above 1508F, researchers will take 50 water specimens at randomly selected times and record the temperature of each specimen. The resulting data will be used to test the hypotheses H0: m 5 1508F versus Ha: m . 1508F.

a. In the context of this example, describe Type I and Type II errors.

b. Which type of error would you consider more serious? Explain.