The percentage of titanium in an alloy used in aerospace castings is measured in 51 randomly selected parts. The sample standard deviation is s = 0.37.
(a) Test the hypothesis using α = 0.05. State any necessary assumptions about the underlying distribution of the data.
(b) Find the P-value for this test.
(c) Construct a 95% two-sided CI for σ.
(d) Use the CI in part (c) to test the hypothesis.