Question

Two different hardening processes (1) saltwater quenching and (2) oil quenching , are used on sample of particular metal alloy. the hardness test results of samples are shown on the table.

Salt water quench 145,150,153,148,141,152,146,154,139,148

Oil quench 152, 150, 147,155,140,146,158,152,151,143

1. Calculate mean values and standard deviation of two processes
2. Construct a 95% confidence between two mean values
3. Chech whether std dev(a) a1^2=a2^2
4. Test the hypothesis that the mean hardeness for saltwater quenching equals oil quenching process. Mar the regions in a digram

Answer 1

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