Dissolved organic compound in lakes. The level of dissolved oxygen in the surface wa...

Dissolved organic compound in lakes. The level of dissolved oxygen in the surface water of a lake is vital to maintaining the lake’s ecosystem. Environmentalists from the University of Wisconsin monitored the dissolved oxygen levels over time for a sample of 25 lakes in the state (Aquatic Biology, May 2010). To ensure a representative sample, the environmentalists focused on several lake characteristics, including dissolved organic compound (DOC). The DOC data (measured in grams per cubic meters) for the 25 lakes are listed in the table on p. 400. The population of Wisconsin lakes has a mean DOC value of 15 grams / m³. Use a hypothesis test (at α = .10) to make an inference about whether the sample is representative of all Wisconsin lakes for the characteristic dissolved organic compound.