The United States Environmental Protection Agency (US EPA) provides a health advisory level for manganese in drinking water of 0.3 milligrams of manganese per liter of sample (mg/L). A water refilling station sent drinking water samples to a local laboratory for analysis of manganese. The analyst tested six subsamples and arrived at the following values: 16.6, 19.8, 15.2, 16.3, 14.9 and 15.7 micromoles of manganese per liter of sample (mol/L).

1) Give the final value that should be reported by the analyst as the concentration of Mn in the drinking water sample. (13 pts)

2) Formulate the null and alternative hypotheses. (2 pts)

3) Construct a 95% confidence interval and provide the conclusion of the test. (10 pts)