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.
(1) Assuming that the variances 𝜎1 2 and 𝜎2 2 are equal,
construct a 95% confidence interval on the difference in mean
hardness.
(2) Construct a 90% confidence interval on the ratio 𝜎1 2 𝜎2 ⁄
2. Does the assumption made earlier of equal variances seem
reasonable?
Two Different Hardening Processes 1 Saltwater Quenching And 2 Oil Quenching Are Used On Samples Of A Particular Ty 1 (24.16 KiB) Viewed 39 times