Consider the water temperature situation described in the previous exercise.

a. For the hypotheses and test procedure described in the previous exercise, calculate the value of b when ? = 153.

b. For the hypotheses and test procedure described in the previous exercise, what is the value of b if ? = 160?

c. What would be the conclusion of the test if H₀ is rejected when z ? 1.8 and x? = 152.4? What type of error might have been made in reaching this conclusion?

Previous exercise

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, a scientist will take 50 water specimens at randomly selected times and will record the water temperature of each specimen. She will then use a z statistic

to decide between the hypotheses H₀: ? = 150 and H_a: ? > 150, where m is the mean temperature of discharged water. Assume that ? is known to be 10.

150 : Vn