Problem 4 (15%). Two different hardening processes, (1) saltwater quenching and (2) oil quenching, are used on samples o

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Problem 4 15 Two Different Hardening Processes 1 Saltwater Quenching And 2 Oil Quenching Are Used On Samples O 1 (67.17 KiB) Viewed 31 times

Problem 4 (15%). Two different hardening processes, (1) saltwater quenching and (2) oil quenching, are used on samples of a particular type of metal alloy. The results are shown in the following table. Assume that hardness is normally distributed. Saltwater Oil (1) Assuming that the variances o? and o² are equal, Quench Quench construct a 95% confidence interval on the difference in mean hardness. 145 152 150 (2) Construct a 90% confidence interval on the ratio 07/2 147 155 Does the assumption made earlier of equal variances seem reasonable? 140 146 158 Please show your steps. 152 151 143 150 153 148 141 152 146 154 139 148