final answers please

Exercise 1 There is concern that increased industrialization may be increasing the mineral content of river water. Ten years ago, the silicon content of the water in a certain river was 5 mg/L. Eightyfive water samples taken recently from the river have mean silicon content 5.4 mg/L and standard deviation 1.2 mg/L. 0] Carry out the appropriate hypothesis test by hand. b] Verify your work in part {a} by using an appropriate confidence interval [Le (a, b], a