An experiment was performed to compare the fracture toughness of high-purity 18 Ni marag...

An experiment was performed to compare the fracture toughness of high-purity 18 Ni maraging steel with commercial- purity steel of the same type (Corrosion Science, 1971: 723–736). For m = 32 specimens, the sample average toughness was for the high-purity steel, whereas for specimens of commercial steel . Because the high-purity steel is more expensive, its use for n = 38a certain application can be justified only if its fracture toughness exceeds that of commercial-purity steel by more than 5. Suppose that both toughness distributions are normal.

a. Assuming that σ₁ = 1.2 and σ₂ =1.1, test the relevant hypotheses using α = .001.

b. Compute β for the test conducted in part (a) when μ₁ – μ₂ = 6.

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