Question

The chemical orthophosphorus content was measured at two different stations on a river. Fifteen samples were collected from station 1 and 12 samples were obtained from station 2. The 15 samples from station 1 had an average orthophosphorus content of 3.84 milligrams per liter and a standard deviation of 3.07 milligrams per liter, while the 12 samples from station 2 had an average content of 1.49 milligrams per liter and a standard deviation of 0.80 milligram per liter.

(a) Construct 98% confidence intervals for σ21/σ22 and σ1/σ2.

(b) If a chemical engineer claims that σ1/σ2>1.5, do the results in (a) support this claim?

Answer 1