Methods for interval estimation and hypothesis
testing about the ratio of expected lifetimes of two independently
distributed two-parameter exponential distribution based on the
concept of generalized variable approach are proposed. As assessed
by simulation, the coverage probabilities of the proposed approach
are found to be very close to the nominal level even for small
samples. The proposed new approaches are conceptually simple and are
easy to use. Similar procedures are developed for constructing
confidence intervals and hypothesis testing about the difference
between means of two independent two-parameter exponential
distribution.