An experiment was performed to compare the frac- ture toughness of high-purity 18 Ni maraging steel with commercial-purity steel of the same type (Cor- rosion Sci., 1971: 723-736). The sample average toughness was x = 65.6 for m = 32 specimens of the high-purity steel, whereas for n = 38 specimens of commercial steel y = 59.8. Because the high- purity steel is more expensive, its use for a certain application can be justi ed only if its fracture tough- ness exceeds that of commercial-purity steel by more than 5. Suppose that both toughness distribu- tions are normal.
a. Assuming that s1 = 1.2 and s2 = 1.1, test the relevant hypotheses using a = .001.
b. Compute b for the test conducted in part (a) when m1 - m2 = 6.