Answer all questions with explanation

An experiment was performed to compare the fracture toughness of high-purity 18 NI maraging steel with commercial-purity steel of the same type. For m = 31 specimens, the sample average toughness was x = 65.2 for the high-purity steel, whereas for n = 36 specimens of commercial steel y = 59.4. Because the high-purity steel is more expensive, its use for a 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 of = 1.4 and oz = 1.0, test the relevant hypotheses using @ = 0.001. (Use #1 - #2, where # is the average toughness for high-purity steel and #2 is the average toughness for commercial steel.) State the relevant hypotheses. O Ho: #1 - H2 = 5 Ha: M1 - 12 > 5 O Ho: M1 - 12 = 5 Ha: #1 - 142