Alkalinity of river water. In Exercise, you learned that the mean alkalinity level of wate...

Alkalinity of river water. In Exercise, you learned that the mean alkalinity level of water specimens collected from the Han River in Seoul, Korea, is 50 milligrams per liter ( Environmental Science&Engineering , September 1, 2000). Consider a random sample of 100 water specimens collected from a tributary of the Han River. Suppose the mean and standard deviation of the alkalinity levels for the sample are, respectively,  mpl and s = 14.4 mpl. Is there sufficient evidence (at α =.01 ) to indicate that the population mean alkalinity level of water in the tributary exceeds 50 mpl?

Alkalinity of river water. The alkalinity level of water specimens collected from the Han River in Seoul, Korea, has a mean of 50 milligrams per liter and a standard deviation of 3.2 milligrams per liter (Environmental Science&Engineering, Sept., 1, 2000). Assume that the distribution of alkalinity levels is approximately normal, and find the probability that a water specimen collected from the river has an alkalinity level

a. exceeding 45 milligrams per liter.

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b. below 55 milligrams per liter.

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c. between 51 and 52 milligrams per liter.